https://www.sciencedirect.com/science/article/pii/S0362546X11004421 (Publisher version)
Bokharaie, V., Mason, O., & Wirth, F. (2011). Stability and positivity of equilibria for subhomogeneous cooperative systems. Nonlinear Analysis: Theory, Methods & Applications, 74(17), 6416-6426. doi:10.1016/j.na.2011.06.023.