TY  - GEN
T1  - The elaboration of school textbooks : methodological guide
A1  - Seguin, Roger
LA  - English
PP  - S.l.
YR  - 1989
UL  - https://gei-testing-vufind.eww-server.de/Record/bnm156918
OP  - 63
KW  - Libros de texto
ER  -