00338nam a2200121Ia 450000500170000000800410001708200120005810000210007024500460009126000300013730000090016765000400017620240814120816.0240813s9999||||xx |||||||||||||| ||und||  a307 JOH  aJohnson, Earl S. 0aTheory and practice of the social studies  aNew YorkbMacmillanc1956  a476p  aSocial science - Teaching/Resesarch