Higgins, Philip J.,  1926- <br/><br/>
Notes on categories and groupoids 
[by] Philip J. Higgins. 
 - London,  New York,  Van Nostrand Reinhold  [1971] 
 - iv, 178 p.  illus.  21 cm. 
 - Van Nostrand Reinhold mathematical studies, 32 .
<br/><br/> On spine: Categories and groupoids. 
<br/><br/>Bibliography: p. 173-174. 
<br/><br/><label>ISBN: </label>442034067 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Groupoids.<br/>Categories (Mathematics)
<br/><br/><label>Dewey Class. No.: </label>512.55 HIG