1. Introduction to Matrix Analysis;Bellman,1970
2. Perspectives in Nonlinearity;Berger Melvyn,1968
3. On the observability of nonlinear systems with application to nonlinear regression analysis;Fitts,1970
4. Some results on existence in uniqueness of solutions of nonlinear networks;Fujisawa;IEEE Trans. Circuit Theory,1971
5. On the observability of nonlinear systems;Griffith;I, J. Math. Anal. Appl.,1971