Gass, I. G.  1926- <br/><br/>
Naming rocks  textures and mineral composition as criteria for rock identification /  [motion picture] : 
I. G. Gass, D. E. Jackson, R. C. I. Wilson 
 - 1 film reel (23 min.) :  sd., b&w. ;  16 mm. +  notes 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Palaeontology.