TY  - GEN
AU  - Olthof,A
AU  - Roberts,W A
TI  - Summation of symbols by pigeons (Columba livia): the importance of number and mass of reward items
SN  - 0735-7036
PY  - 2000///1031
KW  - Animals
KW  - Behavior, Animal
KW  - Choice Behavior
KW  - Columbidae
KW  - Reward
KW  - Size Perception
N1  - Publication Type: Journal Article; Research Support, Non-U.S. Gov't
UR  - https://doi.org/10.1037/0735-7036.114.2.158
ER  -