diff --git a/documentation/query-language.html b/documentation/query-language.html
index 6384280..ee0100c 100644
--- a/documentation/query-language.html
+++ b/documentation/query-language.html
@@ -1,18 +1,17 @@
 <!DOCTYPE html>
-<html>
+<html lang="en">
 <head>
 	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
-	<meta http-equiv="Content-language" content="en">
 	<meta name="description" content="Scalable Reactive Model Transformations">
 	<meta name="MobileOptimized" content="width" />
 	<meta name="HandheldFriendly" content="true" />
 	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
 
 	<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
-	<script type="text/javascript" src="/viatra/js/googleAnalytics.js"></script>
-	<script type="text/javascript" src="/viatra/js/magnific-popup.video.js"></script>
-	<script type="text/javascript" src="/viatra/js/magnific-popup.min.js"></script>
-	<script type="text/javascript" src="/viatra/js/functions.js"></script>
+	<script src="/viatra/js/googleAnalytics.js"></script>
+	<script src="/viatra/js/magnific-popup.video.js"></script>
+	<script src="/viatra/js/magnific-popup.min.js"></script>
+	<script src="/viatra/js/functions.js"></script>
 	<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
 	<script src="/viatra/angular/viatra.js"></script>
 	<script src="/viatra/highlight.js/highlight.min.js"></script>
@@ -25,8 +24,8 @@
 	<link type="text/css" rel="stylesheet" href="/viatra/css/bootstrap.min.css" />
 	<link type="text/css" rel="stylesheet" href="/viatra/css/style.css" />
 	<link type="text/css" rel="stylesheet" href="/viatra/css/media.css" />
-	<link href='https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800' rel='stylesheet' type='text/css'> 
-	<link href='https://fonts.googleapis.com/css?family=Open+Sans+Condensed:300italic,700,300' rel='stylesheet' type='text/css'>
+	<link href="https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800" rel="stylesheet" type="text/css"> 
+	<link href="https://fonts.googleapis.com/css?family=Open+Sans+Condensed:300italic,700,300" rel="stylesheet" type="text/css">
 	<link rel="stylesheet" href="https://use.fontawesome.com/ef6567f233.css">
 
 	<link rel="stylesheet" href="/viatra/highlight.js/styles/foundation.min.css">
diff --git a/index.html b/index.html
index 8642479..1e766eb 100644
--- a/index.html
+++ b/index.html
@@ -1,18 +1,17 @@
 <!DOCTYPE html>
-<html>
+<html lang="en">
 <head>
 	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
-	<meta http-equiv="Content-language" content="en">
 	<meta name="description" content="Scalable Reactive Model Transformations">
 	<meta name="MobileOptimized" content="width" />
 	<meta name="HandheldFriendly" content="true" />
 	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
 
 	<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
-	<script type="text/javascript" src="js/googleAnalytics.js"></script>
-	<script type="text/javascript" src="js/magnific-popup.video.js"></script>
-	<script type="text/javascript" src="js/magnific-popup.min.js"></script>
-	<script type="text/javascript" src="js/functions.js"></script>
+	<script src="js/googleAnalytics.js"></script>
+	<script src="js/magnific-popup.video.js"></script>
+	<script src="js/magnific-popup.min.js"></script>
+	<script src="js/functions.js"></script>
 	<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
 	<script src="angular/viatra.js"></script>
 
@@ -24,8 +23,8 @@
 	<link type="text/css" rel="stylesheet" href="css/bootstrap.min.css" />
 	<link type="text/css" rel="stylesheet" href="css/style.css" />
 	<link type="text/css" rel="stylesheet" href="css/media.css" />
-	<link href='https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800' rel='stylesheet' type='text/css'>
-	<link href='https://fonts.googleapis.com/css?family=Open+Sans+Condensed:300italic,700,300' rel='stylesheet' type='text/css'>
+	<link href="https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800" rel="stylesheet" type="text/css">
+	<link href="https://fonts.googleapis.com/css?family=Open+Sans+Condensed:300italic,700,300" rel="stylesheet" type="text/css">
 	<link rel="stylesheet" href="https://use.fontawesome.com/ef6567f233.css">
 </head>
 
@@ -68,16 +67,16 @@
 			<p>The Eclipse <strong>VIATRA</strong> framework is a model and data transformation tool  that helps move information back and forth in the most efficient way. The  platform focuses specifically on event-driven and reactive transformations,  which happen on-the-fly as the models change. </p>
 			<p>VIATRA is a long-running project that incorporates the results of over 15  years of active research and development. VIATRA offers </p>
 			<ul type="disc">
-			  <li>a       domain-specific language for graph queries and reactive transformations</li>
-			  <li>a Java       runtime library which is scalable and easy to embed.</li>
+			  <li>a domain-specific language for graph queries and reactive transformations</li>
+			  <li>a Java runtime library which is scalable and easy to embed.</li>
 			</ul>
 			<p>VIATRA primarily targets model-driven engineering tools based on the  industry-standard Eclipse Modeling Framework, though it can be used in other  contexts as well. VIATRA is an enabling technology and its biggest benefit is  the power it gives you to close abstraction gaps. These exist in every  data-driven application where structured data needs to be moved across various  languages or representation formats. </p>
 			<p>VIATRA helps you create model transformations that convert objects between  languages. Trivial transformations (i.e. copying pieces of data from one  document to another) are easy with any general purpose programming language  such as Java. In contrast, VIATRA gives you easy-to-use and reusable  programming patterns to address non-trivial transformations, such as </p>
 			<ul type="disc">
-			  <li>Changing       of structure, i.e. converting a UML model to a source code.</li>
-			  <li>Derived       data and abstractions: manipulating data during conversion, e.g. filtering       information for creating &lsquo;abstract views&rsquo;</li>
-			  <li>Combining       multiple sources of information in a significant way to produce a new       result, e.g. when creating data streams for dashboards</li>
-			  <li>Changing       structure: projection of data containing only relevant information during       the conversion phrase </li>
+			  <li>Changing of structure, i.e. converting a UML model to a source code.</li>
+			  <li>Derived data and abstractions: manipulating data during conversion, e.g. filtering information for creating &lsquo;abstract views&rsquo;</li>
+			  <li>Combining multiple sources of information in a significant way to produce a new result, e.g. when creating data streams for dashboards</li>
+			  <li>Changing structure: projection of data containing only relevant information during the conversion phrase </li>
 			</ul>
 		</div>