The AAVSO Archives—Correspondence Collection

The AAVSO Correspondence Collection

ECP—Edward C. Pickering Era—1877-1911—part of Organization Collection

WTO—William Tyler Olcott Era—1911-1915—part of Organization Collection

LC—Leon Campbell Era—1915-1949

MWM—Margaret W. Mayall Era—1949-1973

JAM—Janet A. Mattei Era—1973-2004