TY - BOOK ID - 130325306 TI - The analysis of multilevel data in educational research: studies of problems and their solutions AU - Sellin, N. AU - Cheung, K. C. AU - Keeves, John P PY - 1990 PB - Oxford: Pergamon, DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:130325306 AB - ER -