Leff, L. S. (1997). Barron's geometry the easy way (Third edition.). Barron's Educational Series.
Chicago-Zitierstil (17. Ausg.)Leff, Lawrence S. Barron's Geometry the Easy Way. Third edition. New York: Barron's Educational Series, 1997.
MLA-Zitierstil (9. Ausg.)Leff, Lawrence S. Barron's Geometry the Easy Way. Third edition. Barron's Educational Series, 1997.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.