APA (7th ed.) Citation

Spear, R. E. (1989). Notes on two copper paintings by Domenichino and Guido Reni.

Chicago Style (17th ed.) Citation

Spear, Richard E. Notes on Two Copper Paintings by Domenichino and Guido Reni. 1989.

MLA (9th ed.) Citation

Spear, Richard E. Notes on Two Copper Paintings by Domenichino and Guido Reni. 1989.

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