Merge pull request #1278 from Axelrod-Python/add-paper-on-fsm-memory-algorithm

Add preprint on FSM memory algorithm.

Author: meatballs

citations.md

@@ -2,6 +2,7 @@
 
 ### 2019
 
+* T.J. Gaffney, Marc Harper, Vincent A. Knight. "Memory depth of finite state machine strategies for the iterated prisoner's dilemm" arXiv preprint arxiv:1912.04493 (2019). [ArXiv](https://arxiv.org/abs/1912.04493)
 * Glynatsi, Nikoleta E., and Vincent A. Knight. "Stability of defection, optimisation of strategies and the limits of memory in the Prisoner’s Dilemma." arXiv preprint arxiv:1911.12112 (2019). [ArXiv](https://arxiv.org/abs/1911.12112)
 * Glynatsi, Nikoleta E., and Vincent A. Knight. "A systematic literature review of the Prisoner's Dilemma; collaboration and influence." arXiv preprint arXiv:1911.06128 (2019). [ArXiv](https://arxiv.org/abs/1911.06128)
 * O'Neil, Daniel A., and Mikel D. Petty. "Synthesizing Social Networks with Iterated Prisoners' Dilemma." [Proceedings of the International Conference on Modeling, Simulation and Visualization Methods (MSV).](https://csce.ucmss.com/cr/books/2019/LFS/CSREA2019/MSV2345.pdf) The Steering Committee of The World Congress in Computer Science, Computer Engineering and Applied Computing (WorldComp), 2019.