Cita APA (7a ed.)

De Groot, G. J. (2001). The First World War. Palgrave.

Cita Chicago Style (17a ed.)

De Groot, Gerard J. The First World War. Basingstoke [etc.]: Palgrave, 2001.

Cita MLA (9a ed.)

De Groot, Gerard J. The First World War. Palgrave, 2001.