h2 {margin-bottom: 30px;}
h4 {margin-bottom: 10px;}
.pdf {display: inline-block; padding: 3px; boder: solid 1px darkblue; border-radius: 5px; text-decoration: none; font-weight: bold;}
.pdf:hover {text-decoration: none;}
.paper h4 {margin-bottom: 5px;}
.paper {margin-bottom: 30px;}
/*.authors {}*/
.abstract { text-align: justify}
.keywords {margin: 20px 0;}
.pages, .doi, .udk {margin-top: 10px}