TY  - BOOK
AU  - Holmberg, Borje,
TI  - Theory and practice of distance education
T2  - Routledge studies in distance education
SN  - 0415112923
AV  - LC5800 H65
PY  - 1994///
CY  - London
PB  - Routledge
KW  - Educación a distancia
ER  -