Solving educational problems : the theory and reality of innovation in developing countries 2026-02-15T22:43:01+03:00 DEBUG: VuFind\ILS\Driver\Folio: Token taken from global cache: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiO... - Havelock, Ronald G.; Huberman, A. M (IBE studies and surveys in comparative education, 1977)