Pseudonym the attempt was not entirely successful – and the two are still sometimes confused by booksellers. A pen name may be used specifically to hide the identity of the author, as in the case of exposé books about espionage or crime, or explicit erotic fiction. Some prolific authors adopt a pseudonym to disguise the extent of their published output, e.g. Stephen King writing as Richard Bachman. Co-authors may choose to publish under a collective pseudonym, e.g., P. J. Tracy and Perri O'Shaughnessy. Frederic Dannay and Manfred Lee used the name Ellery Queen as both a pen name for their collaborative
Pen name French-Savoyard writer and poet Amélie Gex chose to publish as Dian de Jeânna ("John, son of Jane") during the first half of her career. Karen Blixen's very successful "Out of Africa" (1937) was originally published under the pen name Isak Dinesen. Victoria Benedictsson, a Swedish author of the 19th century, wrote under the name Ernst Ahlgren. The science fiction author Alice B. Sheldon for many years published under the masculine name of James Tiptree, Jr., the discovery of which led to a deep discussion of gender in the genre. More recently, women who write in genres normally written by men