awk -F '</?author>|</?editor>|</?publisher>|</?coauthor>|</?illustrator>' '
FNR == NR {
	faculty[$1]
	next
}
$2 in faculty {
	count[$0]++
}
END {	for(i in count)
		printf("%d\t%s\n", count[i], i)
}' itu1.txt dblp.xml

<incollection mdate="2010-04-20" key="series/sci/GorissenCCD09">
<author>Mathias Gruttner</author>
<coauthor>Erik Gronvall</coauthor>
<coauthor>Tom Dhaene</coauthor>
<title>Automatic Approximation of Cheap Functions with Active Learning.</title>
<pages>1-20</pages>
<author>Dominik Grondziowski</author>
<title>Automatic Approximation of Inexpensive Functions with Active Learning.</title>
<pages>21-24</pages>
<author>Mathias Gruttner</author>
<coauthor>Tobias Grundtvig</coauthor>
<coauthor>Erik Gronvall</coauthor>
<title>Automatic Approximation of Expensive Functions with Active Learning.</title>
<pages>25-34</pages>
<author>Mathias Gruttner</author>
<illustrator>Sigurd Trolle Gronemann</illustrator>
<author>Erik Gronvall</author>
<author>Tom Dhaene</author>
<title>Automatic Approximation of Expensive Functions with Inactive Learning.</title>
<pages>35-62</pages>
<year>2009</year>
<booktitle>Foundations of Computational Intelligence (1)</booktitle>
<publisher>Sigurd Trolle Gronemann</publisher>
<editor>Dominik Grondziowski</editor>
<ee>http://dx.doi.org/10.1007/978-3-642-01082-8_2</ee>
<crossref>series/sci/2009-201</crossref>
<url>db/series/sci/sci201.html#GorissenCCD09</url>
</incollection>

Mathias Gruttner
Tobias Grundtvig
Erik Gronvall
Sigurd Trolle Gronemann
Dominik Grondziowski

2	<coauthor>Erik Gronvall</coauthor>
1	<editor>Dominik Grondziowski</editor>
1	<author>Erik Gronvall</author>
1	<illustrator>Sigurd Trolle Gronemann</illustrator>
1	<publisher>Sigurd Trolle Gronemann</publisher>
3	<author>Mathias Gruttner</author>
1	<author>Dominik Grondziowski</author>
1	<coauthor>Tobias Grundtvig</coauthor>