Albania   2 studies
Andorra   2 studies
Austria   1260 studies
Belgium   2000 studies
Bosnia and Herzegovina   37 studies
Bulgaria   328 studies
Croatia   256 studies
Czech Republic   959 studies
Denmark   1677 studies
Estonia   252 studies
Finland   815 studies
Former Yugoslavia   4 studies
France   3786 studies
Germany   4450 studies
Greece   593 studies
Hungary   839 studies
Iceland   41 studies
Ireland   351 studies
Italy   2525 studies
Latvia   213 studies
Lithuania   252 studies
Luxembourg   28 studies
Macedonia, The Former Yugoslav Republic of   30 studies
Malta   13 studies
Monaco   1 study
Montenegro   3 studies
Netherlands   2239 studies
Netherlands Antilles   1 study
Norway   1018 studies
Poland   1398 studies
Portugal   499 studies
Romania   544 studies
Serbia   152 studies
Serbia and Montenegro   52 studies
Slovakia   437 studies
Slovenia   134 studies
Spain   2222 studies
Sweden   1306 studies
Switzerland   1471 studies
United Kingdom   3371 studies