00575nam a2200181Ia 4500 0000006351 20251012174451.0 760421s1971 njua b 000 0 eng 0138913331 LB1043 .G318 371.3 Teaching and media; a systematic approach [by] Vernon S. Gerlach [and] Donald P. Ely. Englewood Cliffs, N.J., Prentice-Hall [1971] xiii, 392 p illus 24 cm. Includes bibliographies. Audio-visual education. Teaching Aids and devices. 4116 4116