Rita Lydig, Tragic Mansions
Sometimes in the book world, rare is overused. However, Tragic Mansions is truly is so. No copies are currently available on the resale market, nor were there in 2014, when Nick Harvill Libraries offered a copy signed by Rita Lydig (now sold). There are copies of Tragic Mansions in the collection of libraries in a dozen or so cities. Also, there is the chapter on Rita Lydig in The Power of Style.
Another source on Rita Lydig is the memoir of her younger sister, the nearly as tragic Mercedes de Acosta (but, oh, what adventures both sisters had!). There was a sixteen-year age difference between the two, and In Here Lies the Heart, Mercedes fondly recalls the exquisite Rita treating her as an adult but also acting as her mentor, taking an adolescent Mercedes to Paris and introducing her to Rodin, Boldini, D'Annunzio, Sarah Bernhardt, Edith Wharton, and other luminaries.