1. Karcanias, N. and Giannakopoulos, C., 1983. “Grassman invariants, almost zeros and the determinantal zero, pole assignment problems of linear multivariable systems”. The City Univ.Res.Rep., DSS/NK-CG/236.
2. Karcanias, N., Giannakopoulos, C. and Hubbard, M., 1983. “Almost zeros of a set of polynomials”. Int. J. Control, 38, 1213–1238.
3. MacFarlane, A.G.J. and Karcanias, N., 1976. “Poles and zeros of linear multivariable systems: A survey of Algebraic, Geometric and Complex variable Theory”. Int. J. Control, 24, 33–74.
4. Rosenbrock, H.H., 1970. State space and Multivczriable Theory. Nelson, London.
5. Karcanias, N. and Giannakopoulos, C., 1983. “Exterior Algebra and the problems of pole, zero assignment of linear systems”. Proc. of MECO 83, Athens.