 The Folded Normal Distribution by F. C. Leone and others

F. C. Leone, L. S. Nelson and R. B. Nottingham, Technometrics 3(4), 543–550, November 1961. The publisher abstract motivates the distribution by measurements recorded without their algebraic sign and describes estimation of the underlying normal parameters. The publisher lists 30 April 2012 as the online publication date of the historical article.

Printed p. 543, byline affiliation 1, identifies F. C. Leone with the Case Institute of Technology, Cleveland, Ohio. stat.cmu.edu/technometrics/59-69/VOL-03-04/v0304543.pdf