Cita APA (7a ed.)

Crowley, W. R. (1997). Chemicals on the Internet: A directory of industry sites. Gulf Pub. Co.

Cita Chicago Style (17a ed.)

Crowley, William R. Chemicals on the Internet: A Directory of Industry Sites. Houston, Tex: Gulf Pub. Co, 1997.

Cita MLA (9a ed.)

Crowley, William R. Chemicals on the Internet: A Directory of Industry Sites. Gulf Pub. Co, 1997.