1. Brändén, P.: Obstructions to determinantal representability. Adv. Math. 226, 1202–1212 (2011). http://arxiv.org/pdf/1004.1382.pdf
2. Choe, Y., Oxley, J., Sokal, A., Wagner, D.G.: Homogeneous multivariate polynomials with the half-plane property. Adv. Appl. Math. 32, 88–187 (2004). http://arxiv.org/pdf/math/0202034.pdf
3. Gårding, L.: An inequality for hyperbolic polynomials. J. Math. Mech. 8, 957–965 (1959)
4. Güler, O.: Hyperbolic polynomials and interior point methods for convex programming. Math. Oper. Res. 22, 350–377 (1997)
5. Helton, J., Vinnikov, V.: Linear matrix inequality representation of sets. Comm. Pure Appl. Math. 60, 654–674 (2007). http://arxiv.org/pdf/math/0306180.pdf