McDonald, Jerry N. <br/><br/>
The Autochthonous North American musk oxen bootherium, symbos, and gidleya (mammalia  artiodactyla  bovidae) / 
Jerry N. McDonald and Clayton E. Ray 
 - Washington :  Smithsonian Institution Press,  1989 
 - iii, 77 p. :  ill. ;  28 cm. 
 - Smithsonian contributions to paleobiology  no. 66 .
<br/><br/>Bibliography : p. 74-77 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Muskox, Fossil--North America--Classification<br/>Paleontology--North America