1. Hwang, F.K., Richards, D.S., Winter, P.: The Steiner Tree Problem. Elsevier Science Publishers, Amsterdam (1992)
2. Brazil, M., Rubinstein, J.H., Thomas, D.A., Weng, J.F., Wormald, N.C.: Gradient constrained minimum networks (I). Fundamentals. Journal of Global Optimization 21(2), 139–155 (2001)
3. Brazil, M., Thomas, D.A.: Network optimisation for the design of underground mines. Networks 49(1), 40–50 (2007)
4. Lane, K.F.: The Economic Definition of Ore—Cutoff Grade in Theory and Practice. Mining Journal Books Limited, London (1988)
5. Nehring, M., Topal, E.: Production Schedule Optimisation in Underground Hard Rock Mining Using Mixed Integer Programming. Project Evaluation Conference, The Australasian Institute of Mining and Metallurgy, vol. 4, pp. 169–175 (2007)