TY  - BOOK
AU  - Verduin,John R
AU  - Clark,Thomas A.
TI  - Distance education: the foundations of effective practice 
AV  - LC5800 .D578 1991
PY  - 1991///
CY  - San Francisco
PB  - Jossey-Bass
KW  - Distance education
N1  - 1 (pages 241-267) and indexes; 2
ER  -