The emergence of pictures and their utilization for visual communication in the Agricultural Extension Service
Subtitle: Pennsylvania -- 1914-1949
By: by George Fiske Johnson.
Publisher: Pennsylvania Agricultural and Home Economics Extension Service, Pennsylvania State University?]
Published: 1967
Place of publication: [University Park, Pa.?
Language: eng
Number of pages: 36
Subjects: Agriculture -- Study and teaching -- Audio-visual aids.; Agricultural extension work -- Pennsylvania.
Notes: Includes bibliographical references.