The audio-visual handbook
By: by Ellsworth C. Dent
Contributors: Society for Visual Education
Edition: 6th ed.
Publisher: Society for Visual Education
Published: 1949
Place of publication: Chicago
Language: eng
Number of pages: 220
Subjects: Audio-visual education
Notes: First ed., 1934, published under title: A handbook of visual instruction.

"Sources of information, materials and equipment": p. 195-220.