Cita APA (7a ed.)
Provost, L., & Norman, C. Variation through the ages.
Cita Chicago Style (17a ed.)
Provost, L.P, y C.L Norman. Variation Through the Ages.
Cita MLA (9a ed.)
Provost, L.P, y C.L Norman. Variation Through the Ages.
Precaución: Estas citas no son 100% exactas.