Gradation by water
Subtitle: a guide for use with the educational sound pictures "The work of rivers" and "Ground water"
By: prepared by Melvin Brodshaug ... in collaboration with Carey Croneis ... and H.C. Bryant & Earl A. Trager ...
Contributors: Croneis, Carey, 1901- joint author.; Bryant, H. C. b. 1886, joint author.; Trager, Earl A. 1899- joint author.; Encyclopaedia Britannica Films, inc.
Publisher: The University of Chicago press
Published: 1937
Place of publication: Chicago, Ill
Language: eng; ger
Number of pages: 51
Subjects: Erosion.; Rivers.; Groundwater.
Notes: "References": p. 51-[52]
"The study guide is based upon research in the utilization of educational sound films carried on by Erpi picture consultants, inc."--Foreword.