1. [1] E. Ising, “Beitrag zur theorie des ferromagnetismus,” Zeitschrift für Physik, vol. 31, no. 1, pp. 253-258, 1925.
2. [2] R.M. Karp, “Reducibility among combinatorial problems,” in Complexity of Computer Computations, pp. 85-103, Boston, MA: Springer US, 1972.
3. [3] A. Galluccio, M. Loebl, and J. Vondrák, “New algorithm for the Ising problem: Partition function for finite lattice graphs,” Physical Review Letter, vol. 84, no. 26, pp. 5924-5927, 2000.
4. [4] Z. Wang, A. Marandi, K. Wen, R.L. Byer, and Y. Yamamoto, “Coherent Ising machine based on degenerate optical parametric oscillators,” Physical Review A, vol. 88, no. 6, p. 063853 (9 pages), 2013.
5. [5] Z. Wang, Coherent computation in Degenerate Optical Parametric Oscillators, PhD thesis, Stanford University, Stanford University, Stanford, CA 94305 USA, 2015.