Rafiqi, M., Lemke, S., Ferguson, S., Stauber, M., & Schmidt-Ott, U. (2008). Evolutionary origin of the amnioserosa in cyclorrhaphan flies correlates with spatial and temporal expression changes of zen. Proceedings of the National Academy of Sciences of the United States of America, 105(1), 234-239. Retrieved from http://www.pnas.org/content/105/1/234.full.