APA (7th ed.) Citation

Steen, P. v. d. (1968). On differential operators of infinite order. Waltman.

Chicago Style (17th ed.) Citation

Steen, Pleun van der. On Differential Operators of Infinite Order. Delft: Waltman, 1968.

MLA (9th ed.) Citation

Steen, Pleun van der. On Differential Operators of Infinite Order. Waltman, 1968.