Bŭlgarska akademii︠a︡ na naukite. T︠S︡entŭr za nauchna informat︠s︡ii︠a︡ i dokumentat︠s︡ii︠a︡.
Bŭlgarska akademii︠a︡ na naukite. Scientific Information Centre for Natural, Mathematical and Social Sciences.
aTsentur za nauchno-tekhnicheska informatsiia i dokumentatsiia (Bulgaria)