Kail ,Robert V. Cavanaugh , John C. Human Development : A Life Span View - Third ed. - Thomson , Singapore : 2004 - xxv , 751 p. : 28 cm ISBN: 0534597513 Nat. Bib. Agency Control No.: 304.2 KAL Subjects--Topical Terms: Human Ecology / මානව පරිසරය Dewey Class. No.: 304.2