"1981 Nebula Awards". The Locus Index to SF Awards. Locus Publications. Archived from the original on June 5, 2011. Retrieved April 10, 2015.
sfwa.org
"Bob Leman (1922–2006)". Fantasy and Science Fiction News. Science Fiction and Fantasy Writers of America. August 8, 2006. Archived from the original on August 11, 2006. Retrieved June 28, 2017.
web.archive.org
"Bob Leman (1922–2006)". Fantasy and Science Fiction News. Science Fiction and Fantasy Writers of America. August 8, 2006. Archived from the original on August 11, 2006. Retrieved June 28, 2017.
"1981 Nebula Awards". The Locus Index to SF Awards. Locus Publications. Archived from the original on June 5, 2011. Retrieved April 10, 2015.