"zero-sum." YourDictionary, n.d. Web. 15 September 2018. <http://www.yourdictionary.com/zero-sum>.
zero-sum. (n.d.). Retrieved September 15th, 2018, from http://www.yourdictionary.com/zero-sum
Of or relating to a situation in which a gain is offset by an equal loss: “Under the zero-sum budgeting system that governs federal spending, the money for spinal research is likely to be deducted from some other research account” ( Daniel S. Greenburg )