Orth, T., Knittel, P., & Sippel, J. (1981). A selected bibliography on photographic conservation, January 1975-December 1980 ([2nd ed.].). Rochester, N.Y.: Technical and Education Center of the Graphic Arts, College of Graphic Arts and Photography, Rochester Institute of Technology.

Orth, Thomas., Patricia Knittel, and John Sippel. A Selected Bibliography On Photographic Conservation, January 1975-December 1980. [2nd ed.]. Rochester, N.Y.: Technical and Education Center of the Graphic Arts, College of Graphic Arts and Photography, Rochester Institute of Technology, 1981.

Orth, Thomas., Patricia Knittel, and John Sippel. A Selected Bibliography On Photographic Conservation, January 1975-December 1980. [2nd ed.]. Rochester, N.Y.: Technical and Education Center of the Graphic Arts, College of Graphic Arts and Photography, Rochester Institute of Technology, 1981.