00556nam a22002057a 450000500170000001000110001702000100002803500110003803700160004904000120006508200160007710000230009324500590011626000400017527000140021530000210022950000390025065000280028965000330031720170124105933.0  a852168  c00.00  a852168  bCen Lib/Ret  aDPLbEN  a371.33bCHA  aChakravarty, S. R.  aAudio visual aids in education /cby S. R. Chakravarty  aNew DelhibSagar publicationsc1977  bNew Delhi  a112p. c21cm(Hb)  aIncludes bibliographical reference  a Audio-visual education  aTeaching -- Aids and devices