Shumaker, R W <br/><br/>
Spontaneous use of magnitude discrimination and ordination by the orangutan (Pongo pygmaeus).  [electronic resource] 

 -  Journal of comparative psychology (Washington, D.C. : 1983)  Dec 2001 
 - 385-91 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0735-7036 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Animals<br/>Appetitive Behavior<br/>Attention<br/>Discrimination Learning<br/>Female<br/>Male<br/>Motivation<br/>Pongo pygmaeus--psychology<br/>Problem Solving