...Mechanical concentration of gases
By: by C. G. Maier.
Series: U. S.  Bureau of Mines.  Bulletin 431
Publisher: U.S. Govt. Print. Off.
Published: 1940
Place of publication: Washington
Language: eng
Number of pages: 148
Subjects: Gases; Diffusion
Notes: Bibliography: p. 148.
At head of title: United States Dept. of the Interior, Harold L. Ickes, secretary.  Bureau of Mines, R. R. Sayers, director.