Memoirs of the American Mathematical Society, ISSN 0065-9266 ; Volume 91, Number 446
Print version: Lawlor, Gary R. (Gary Reid), 1961- Sufficient criterion for a cone to be area-minimizing. Providence, Rhode Island : American Mathematical Society, c1991 vi, 111 pages Memoirs of the American Mathematical Society ; Volume 91, Number 446. ISBN 9780821825129
"May 1991, volume 91, number 446 (third of 4 numbers)."