Studium na temat woli walki w działanaich bojowych: Connable, Ben, Michael J. McNerney, William Marcellino, Aaron Frank, Henry Hargrove, Marek N. Posard, S. Rebecca Zimmerman, Natasha Lander, Jasen J. Castillo, and James Sladden, Will to Fight: Analyzing, Modeling, and Simulating the Will to Fight of Military Units. Santa Monica, CA: RAND Corporation, 2018.