The practice of social research / Earl Babbie. - 6th ed.. - Belmont : Wadsworth publ. comp., [1992]. - xxii, 493, [148] p. : fig. ; 23 cm.см.. - Bibliogr.: p. B1-B6. - ISBN 0-534-15576-6 : [n. p.][MFN: 17103]
The practice of social research / Earl Babbie. - 3rd ed.. - Belmont : Wadsworth Inc., [1983]. - xxiv, 551 p. : fig. ; 24 cm.см.. - Bibliogr.: p. 527-531. - [n. p.][MFN: 18459]