Describing function-based analysis of a nonlinear hydraulic transmission line. - L. J. Heyns; Johan J. Kruger (IEEE Trans. Control. Syst. Technol., 1994)

An Introduction to an Egocentric Concept of Machine Intelligence. - Rudolph Pienaar; Johan J. Kruger (Int. J. Artif. Intell. Tools, 1999)