Olthof, A <br/><br/>
Summation of symbols by pigeons (Columba livia): the importance of number and mass of reward items.  [electronic resource] 

 -  Journal of comparative psychology (Washington, D.C. : 1983)  Jun 2000 
 - 158-66 p.  digital 
<br/><br/> Publication Type: Journal Article; Research Support, Non-U.S. Gov't 
<br/><br/><label>ISSN: </label>0735-7036 
<br/><br/><label>Standard No.: </label>10.1037/0735-7036.114.2.158  doi 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Animals<br/>Behavior, Animal<br/>Choice Behavior<br/>Columbidae<br/>Reward<br/>Size Perception