By Hendrick Ruth   Hightower William   Gregory Dennis   in Community College Journal of Research and Practice

ISSN:1521-0413|30|8|627-640

Routledge Ltd‎(2006)‎

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By Harger Robert T.   Hightower William L.   in The College Mathematics Journal

ISSN:1931-1346|40|3|213-214

Mathematical Association of America‎(2009)‎

Access to resources Favorite 9.181461