TY  - BOOK
AU  - Ryan,William T.
TI  - A guide to marketing
PY  - 1981///
CY  - Homewood, Ill.
PB  - Learning Systems Co.
KW  - Marketing
N1  - 'An adaptation of material previously published in a programmed learning aid (PLAID) entitled Principles of marketing - t.p. verso; Includes index
ER  -