APA (7th ed.) Citation

Marks, S. P. (1994). Grey Powys books. [Powys Society].

Chicago Style (17th ed.) Citation

Marks, Stephen Powys. Grey Powys Books. [England]: [Powys Society], 1994.

MLA (9th ed.) Citation

Marks, Stephen Powys. Grey Powys Books. [Powys Society], 1994.

Warning: These citations may not always be 100% accurate.