Hayes AF, Montoya AK, Rockwood NJ. The analysis of mechanisms and their contingencies: PROCESS versus structural equation modeling. AMJ. 2017 Feb;25(1):76-81. doi: 10.1016/j.ausmj.2017.02.001
Brogan AJ, Stidham S. A note on separation in mean-lower-partial-moment portfolio optimization with fixed and moving targets. IIE Trans. 2005 Jan 1;37(10):901-6.