1. Cheng, Ching-Shui, Optimality of certain asymmetrical experimental designs. Ann. Statist., 6, 1239–1261 (1978).
2. Gaffke, N., Optimale Versuchsplanung für lineare Zwei-Faktor-Modelle. Ph. D.-Thesis, RWTH Aachen 1978.
3. Gaffke, N., Krafft, O., Optimum properties of latin square designs and a matrix inequality. Math. Operationsforsch. Statist., Ser. Statistics, 8, 345–350 (1977).
4. John, P.W.M., Statistical design and analysis of experiments, Macmillan, New York 1971.
5. Krafft, O., Lineare statistische Modelle und optimale Versuchspläne, Vandenhoeck u. Ruprecht, Göttingen 1978.