J. Hidayati, S. Sukardi, A. Suryani, S. Sugiharto, and A. M. Fauzi, “Analysis of Productivity Improvement in the Palm Oil Plantation Revitalization of North Sumatera using Analytic Network Process”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 4, no. 3, pp. 162–168, Jun. 2014.