Zaini, S.N.A.M., and M.Y. Abu. “Implication of Time Equation in Mature and Immature Area of Ramp Using Time Driven Activity-Based Costing”. Journal of Modern Manufacturing Systems and Technology, vol. 4, no. 2, Sept. 2020, pp. 36-39, doi:10.15282/jmmst.v4i2.4884.