ACKNOWLEDGMENTS
Our thanks to those authors who permitted the use of their stories, and to the estates and their representatives who intervened for those authors unreachable without time travel (we raise a glass to absent friends). Among the very helpful agents deserving thanks are Spectrum Literary Agency, Richard Curtis Associates, the Zeno Literary Agency, and the Virginia Kidd Literary Agency. And thanks for help and advice from others I’m unforgivably forgetting. Gratitude is also due to the Internet Speculative Fiction Database (ISFDB.org) for existing and being a handy source of raw data, and to the devoted volunteers who maintain that very useful site.