collier's encyclopedia (full title: collier's encyclopedia with bibliography and index) is a discontinued united states-based general encyclopedia published by crowell, collier and macmillan. self-described in its preface as "a scholarly, systematic, continuously revised summary of the knowledge that is most significant to mankind", it was long considered one of the three major contemporary english-language general encyclopedias, together with "encyclopedia americana" and "encyclopædia britannica": the three were sometimes collectively called "the abcs".