Defined as:
Amber R Paden, Tiffany Kodak, Wayne W Fisher, Elizabeth M Gawley-Bullington, Kelly J Bouxsein
J Appl Behav Anal. 2012 Summer; 45(2): 425–429. doi: 10.1901/jaba.2012.45-425
Rocio Rosales, Karen Stone, Ruth Anne Rehfeldt
J Appl Behav Anal. 2009 Fall; 42(3): 541–549. doi: 10.1901/jaba.2009.42-541
Julie M Marckel, Nancy A Neef, Summer J Ferreri
J Appl Behav Anal. 2006 Spring; 39(1): 109–115. doi: 10.1901/jaba.2006.131-04