Novak, A. <https://pure.iiasa.ac.at/view/iiasa/2248.html>, Kaitala, V., & Feichtinger, G. <https://pure.iiasa.ac.at/view/iiasa/2589.html>  (1995).  Resource leasing and optimal periodic capital investments.   Zeitschrift fuer Operations Research 42 (1) 47-67. 10.1007/BF01415673 <https://doi.org/10.1007/BF01415673>.