Albania   3 studies
Andorra   3 studies
Austria   1352 studies
Belgium   2128 studies
Bosnia and Herzegovina   43 studies
Bulgaria   363 studies
Croatia   279 studies
Czech Republic   1034 studies
Denmark   1764 studies
Estonia   272 studies
Finland   868 studies
Former Yugoslavia   7 studies
France   4067 studies
Germany   4784 studies
Greece   638 studies
Hungary   901 studies
Iceland   43 studies
Ireland   364 studies
Italy   2715 studies
Latvia   229 studies
Lithuania   269 studies
Luxembourg   26 studies
Macedonia, The Former Yugoslav Republic of   34 studies
Malta   14 studies
Monaco   2 studies
Montenegro   4 studies
Netherlands   2383 studies
Netherlands Antilles   1 study
Norway   1090 studies
Poland   1486 studies
Portugal   516 studies
Romania   609 studies
Serbia   184 studies
Serbia and Montenegro   43 studies
Slovakia   475 studies
Slovenia   146 studies
Spain   2413 studies
Sweden   1404 studies
Switzerland   1551 studies
United Kingdom   3582 studies