00401nam a22001577a 450000100060000000300100000600500170001604000140003300800410004702000180008810000250010624500240013126000620015530000110021765000150022811637MX-SIABUC20260702204317.0  aMX-SIABUC050525s1972    -usx   j            eng d  a0-231-03665-540aNielsen, Waldemar A.0 aThe big foundations4 aEstados Unidos de América :bThe Twuntieth Century Fund4 a475 p.  a1.EMPRESAS