question: Are both Pray the Devil Back to Hell and Diana's Hair Ego documentary films?
answer: yes
context: Title: Pray the Devil Back to Hell
  Passage: Pray the Devil Back to Hell is a documentary film directed by Gini Reticker and produced by Abigail Disney.  The film premiered at the 2008 Tribeca Film Festival, where it won the award for Best Documentary.  The film had its theatrical release in New York City on November 7, 2008.
  Title: Zhou Bing
  Passage: Zhou Bing (simplified Chinese: 周兵; pinyin: Zhōu Bing , Zhoubing ; born 1 April 1968), famous Chinese documentary director, a PhD from History College of Nankai University, have successively served as the column scenarist and special program production manager of the program titled with “Oriental Biography” and director of special program division of CND Film Group.  Zhou Bing was titled with annual director of Chinese documentary film for three times, and the documentary films created and produced by him amounts to 100 hundred units.  His masterpieces including Palace, Dun Huang and "Road of Millenia Bodhi were" aired on CCTV, National Geographic, SKY TV, History Channel, Arte, and NDR.  Currently he establishes Beijing Oriental Elites Culture Development Co Ltd and works with Tiong Hiew King, the datuk of Tan Sri, Malaysia to setup Sun Media International Co. Ltd and Zero Media International Co. Ltd.  Zhou Bing attempted to join in the development of industrialization process of documentary films with the identity of independent directors.  Zhou Bing is also a Adjunct Professor in the Department of Media and Communication of City University of Hong Kong.  It is art dream of Mr Zhou who has been desiring to realize through images to broadcast Chinese culture and to build oriental aesthetic approach with the images recognized by the world.
  Title: Diana's Hair Ego
  Passage: Diana's Hair Ego is an American documentary film about AIDS and one unconventional woman's efforts to educate her small, Southern community.  While documenting an AIDS quarantine controversy in South Carolina with DIVA TV (Damned Interfering Video Activist TV), filmmaker Ellen Spiro met DiAna DiAna, a local hairdresser who transformed her beauty parlor into a center for AIDS and safe sex information.
citations: Diana's Hair Ego Pray the Devil Back to Hell