TY  - BOOK
AU  - Tribe,Michael A.
AU  - Eraut,Michael
AU  - Snook,Roger K.
TI  - Ecological principles
T2  - Basic biology course ; book 4 : Unit 2, Organisms and their environment
SN  - 0521206588.
U1  - 574.52 
PY  - 1975///
CY  - Cambridge [Eng.], New York
PB  - Cambridge University Press
KW  - Ecology
KW  - Programmed instruction
N1  - Bibliography: p. 158 and index
ER  -