Title: Materiali za nat︠s︡ionalen kurs po problemi na obrazovanieto za opazvane na okolnata sreda, organiziran ot MNP, T︠S︡IUURK, sŭvmestno s I︠U︡NESKO, ot 4 i︠u︡ni, gr. Sofii︠a︡
Subjects: Study and teaching, Congresses, Environmental protection, Nature conservation