"zero-sum." YourDictionary, n.d. Web. 09 November 2018. <https://www.yourdictionary.com/zero-sum>.
zero-sum. (n.d.). Retrieved November 09th, 2018, from https://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 )