There is a wealth of historical information in the Regis class yearbooks. Copies are located in the library -- ask at Circulation or the Reference & Research Help Desk.
For the yearbooks, the publisher is often not known. Look in the back of the book on the last few pages to see if it is mentioned. If the publisher is mentioned, use these as an example:
APA (for yearbooks found in the digital collection):
Regis College. (1950). Mount Regis, 1950. Internet Archive. The Andover Press. https://archive.org/details/mountregis1950regi
Regis College. (1931). Mount Regis, 1931. Internet Archive. The Brandow Printing Company.
https://archive.org/details/mountregis1931regi
MLA:
Regis College. Mount Regis, 1950. Andover: The Andover Press, Ltd., 1950. Print. Archives, Regis College Library.
Regis College. Regis Tower, 1931. Albany: The Brandow Printing Company, 1931. Print. Archives, Regis College Library.
Use this example when no publisher information can be located:
Regis College. The Mount Regis, 1975. Weston: Graduating Class of 1975. Print. Archives, Regis College Library.