00733nam a2200241Ia 4500003000600000005001700006008004100023020002100064035002000085040001600105082001600121100002000137245008000157250001200237260003500249300001900284650003400303650002700337650002800364650002000392650003200412700004700444OCoLC20151023231626.0900703@@@@@@@@@sa           @    @ eng d  a0409099252 (pbk)  a(OCoLC)86067163  cAP Akademie04a371.3342211 aConradie, P. J.10aVan onderrighulpmiddel tot sisteemonderrig /cP J Conradie, P G du Plessis.  a2nd ed.  aDurban :bButterworth,cc1980.  a157 p. :bill. 0aEducationxAudio-visual aids. 0aInstructional systems. 0aEducational technology. 0aTechnical aids. 0aTeachingxAids and devices.1 aDu Plessis, P. G.q(Pieter George),d1947-