Memoirs of the American Mathematical Society, ISSN 0065-9266 ; Volume 69, Number 371
Print version: Figueiredo, Leila, 1952- Calculus of principally twisted vertex operators. Providence, Rhode Island : American Mathematical Society, c1987 iv, 58 pages Memoirs of the American Mathematical Society ; Volume 69, Number 371. ISBN 9780821824344
"September 1987, Volume 69, Number 371 (first of 2 numbers)."