Sally, Judith D. Roots to research : a vertical development of mathematical problems / Judith D. Sally, Paul J. Sally, Jr. - Providence, R.I. : American Mathematical Society, 2012 - xiii, 338 p. : ISBN: 9780821844038 (alk. paper) Subjects--Topical Terms: Mathematics--Research. Universal Decimal Class. No.: 51:001.8 / SAL