Bakker, W. F. (1966). The Greek imperative: An investigation into the aspectual differences between the present and aorist imperatives in Greek prayer from Homer up to the present day. A.M. Hakkert.

Bakker, Willem Frederik. The Greek Imperative: An Investigation into the Aspectual Differences Between the Present and Aorist Imperatives in Greek Prayer from Homer Up to the Present Day. Amsterdam: A.M. Hakkert, 1966.

Bakker, Willem Frederik. The Greek Imperative: An Investigation into the Aspectual Differences Between the Present and Aorist Imperatives in Greek Prayer from Homer Up to the Present Day. A.M. Hakkert, 1966.