00386nam a2200145Ia 4500008004100000082001600041100002000057245003100077260004700108300000800155650001400163650002000177653002000197653002300217170901s1967    xx            000 0 und d  a374.4bE77T  aErdos, Renee F. 0aTeaching by Correspondence  aParisbLongman, Green and Co Limitedc1967  a218  aEducation  aSocial sciences  aAdult education  aDistance education