Cita APA (7a ed.)

Kreft, I., & Leeuw, J. d. (1999). Introducing multilevel modeling. Sage.

Cita Chicago Style (17a ed.)

Kreft, Ita, y Jan de Leeuw. Introducing Multilevel Modeling. London [etc.]: Sage, 1999.

Cita MLA (9a ed.)

Kreft, Ita, y Jan de Leeuw. Introducing Multilevel Modeling. Sage, 1999.