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
Caso P, Sutherland GR, Fleming A, McDicken WN. Doppler tissue imaging: current status and future prospects. G Ital Cardiol. 1995 May 1;25(5):639-47.