H.J, K. et al.(1990).Asas-asas penelitian behavioral / Fred N. Kerlinger; Londong R. Simatupang, H.J Koesoemanto (Ed.ke-3).:Gadjah Mada University Press.
Gaya MLA
Koesoemanto, H.J. et al."Asas-asas penelitian behavioral / Fred N. Kerlinger; Londong R. Simatupang, H.J Koesoemanto".Ed.ke-3:Gadjah Mada University Press,1990.Textbook.