Note: E. R. Royce is known only for the 1954 novel, which may be pseudonymous. (WorldCat reports 4 works by "Royce, E R" as an undifferentiated name, this one and three literary educational work published in Australia.) The Encyclopedia of Science Fiction formerly (1993, print) attributed the work to Denis Hughes, retracted in SFE3 (online 2011, viewed at Internet Archive).