USA:

H.477-H.480: Correspondence with colleagues at Rutgers University, New Brunswick, New Jersey, and others, 1957-1981.

H.481-H.482: Correspondence with colleagues at Berkeley, principally Melvin Calvin and others at the Laboratory of Chemical Biodynamics, 1977-1988.

H.483-H.493: Correspondence with colleagues at University of Wisconsin-Madison regarding research collaboration in the field of penicillin and cephalosporin biosynthesis, visits etc. Abraham's principal correspondent is C.J. Sih of the School of Pharmacy. 1973-1986.

USSR:

H.494-H.495: Correspondence with colleagues regarding research, visits, etc., 1960-1984.