Question: Patricia Burford Ryan, an American writer of romance novels,  is the twin sister of the romance writer Pamela Burford whose books are currently available as what type of books?
Context: Judith Gould is a fictional American writer of romance novels, and is the pseudonym used by co-authors: Nicholas Peter "Nick" Bienes and Rhea Gallaher, who are actually both men.  Gould is a "New York Times" bestselling author whose books have been translated into 22 languages. Rosemary Pollock (born 1944) was a British writer of a dozen romance novels from 1968 to 1981.  She is the daughter of the centenarian romance writer and painter Ida Pollock (1908-2013) and Lieut Colonel Hugh Alexander Pollock D.S.O. Royal Scots Fusilers (1888–1971). Anne Gracie is an award winning Australian author of historical romance novels.  Her books have been shortlisted for RITA Award and she has twice won the Australian Romance Writer of the Year award and National Readers Choice Award (USA).  She lives in Melbourne, Victoria. Pamela Brooks (born 11 February 1966 in Essex, England) is a British writer of non-fiction books, she also writes romance novels under the pseudonym of Kate Hardy, and erotic novels as Lucinda Chester, Evelyn D'Arcy, Chelsea Miller and Pamela Rochford.  Her novels won two Love Story of the Year by the Romantic Novelists' Association, in 2008, "Breakfast at Giovanni's", and in 2014, "Bound by a Baby". Sally Wentworth was the pseudonym used by Doreen Hornsblow (died 2001), a British romance writer of 70 romance novels in Mills & Boon's from 1977 to 1999. According to Tatin Yang in the article "Romansang Pinoy: A day with Tagalog romance novels", Tagalog romance paperbacks were thin Philippine versions of romance novel books that could be found at the bottom shelves of the romance section of bookstores, wrapped and bound with book covers that are decorated with Philippine comics-styled illustrations, such as "a barrio landscape with a badly dressed guy and girl locked in an embrace".  As a form of "escapist fiction" (escapism) and "commercial literature", Tagalog romance novels generally follow a "strict romance formula", meaning the narratives have happy endings (a factor influencing the salability of the novel), the protagonists are wealthy, good-looking, smart, and characters that cannot die.  Normally, the hero or heroine of the story falls in love and "goes crazy" over the admired person.  However, later authors of Tagalog romance novels deviated from portraying so-called "damsel-in-distress and knight-in-shining-armor characters".  Contemporary writers also turned away from writing "rags-to-riches plots".  The stereotypical norm had been replaced by the incorporation of storylines with "interesting scenes, characters [who are ready to face challenges or to sacrifice themselves for the benefit of other people], dialogues, and new angles to old plots".  Authors such as Maria Teresa Cruz San Diego, who used the pen names Maia Jose and Tisha Nicole, ventured into the fantasy romance genre, and into topics that are related to politics, ecology, gender issues, prostitution, mail-order bride syndicates, white slavery, non-governmental organizations, and breastfeeding programs.  Apart from writing about ideal lovers (men and women) and ideal situations, other novelists wrote about true-to-life settings, or at least based the stories from personal experiences.  Thus, Tagalog romance novels came to mirror or replicate the "roles that women and men play" in Philippine society. Patricia Burford Ryan (born August 9, 1954 in Las Cruces, New Mexico, United States) is an American writer of romance novels as Patricia Ryan and mystery novels as P.B. Ryan.  She is the twin sister of the romance writer Pamela Burford. Barbara McCauley is a popular romance writer.  She has written over 35 romance novels for Harlequin Enterprises since 1991. Pamela Burford (born August 9, 1954 in Las Cruces, New Mexico, United States) is an American novelist.  She is an award-winning author of 14 contemporary romance and romantic suspense novels, and she is the twin sister of the author Patricia Ryan (aka P.B. Ryan).  Most of Pamela's novels are currently available as ebooks. Mary Tate Engels (born March 27, 1943) is an American writer of almost thirty romance novels since 1982 as Tate McKenna and Mary Tate Engels.  She has co-written five romance novels under the pseudonyms Cory Kenyon and Corey Keaton with Vicki Lewis Thompson and two non-fiction books for Texas Tech University Press.  She lives with her husband in Tucson, Arizona.
Answer: ebooks