Leedy, Paul D. Practical research : planning and design. - 7th ed. / Paul D. Leedy, Jeanne Ellis Ormrod. - Upper Saddle River, N.J. : Merrill Prentice Hall, 2001. - xx, 318 p. : ill. ; 28 cm. Includes bibliographical references and index. ISBN: 0139603603 LCCN: 00034859 Subjects--Topical Terms: Research--Methodology. LC Class. No.: Q180.55.M4 / L43 2001 Dewey Class. No.: 001.4