American | Association football | association football | American Civil War | American Broadcasting Company | American football | African American | American Idol | Forward (association football) | American Revolutionary War | Goalkeeper (association football) | Defender (association football) | American Revolution | National Basketball Association | American Association for the Advancement of Science | American Red Cross | Association of Tennis Professionals | American Library Association | American Museum of Natural History | American Express | World Boxing Association | National Collegiate Athletic Association | American Academy of Arts and Sciences | American League | American Association | American Heart Association | American comic book | American Institute of Architects | American Airlines | American Hockey League |
Crelin was a member of the American Association of Anatomists, Sigma Xi, AAAS and AMA, served as associate editor of the Anatomical Record from 1968 to 1974 and was an editor for Gray's Anatomy
He was a member of Sigma Xi, Phi Kappa Phi, and Phi Zeta; a Fellow of the American Association for the Advancement of Science, a member of the American Association of Anatomists, the American Society of Mammalogists, the Histochemical Society, the Society for the Study of Reproduction, and the American Society of Zoologists.