Arakawa, A., Suarez, M.J., 1983: Vertical differencing of the primitive equations in sigma coordinates., Mon. Wea. Rev., 111, 34-45.
Asselin, R., 1972: Frequency Filter for Time Integrations, Mon. Wea. Rev., 100, 487-490.
Manabe, S., Smagorinsky, J., and Strickler, R. F., 1965: Simulated climatology of a general circulation model with a hydrologic cycle. Mon. Weather Rev., 93, 769-798.