[1] A. P. Sage, N. J. Guinzy: Identification and modelling of large-scale systems using sensitivity analysis. Internat. J. Control 17 (1973), 5, 1073-1087. Zbl 0257.93004

[2] E. J. Davison: A method for simplifying linear dynamic systems. IEEE Trans. Automat. Control AC-11 (1966), 1, 93-101.

[3] H. Heffes, P. E. Sarachnik: Uniform approximation of linear systems. Bell System Tech. J. 48 (1969), 209-231. MR 0235865

[4] N. K. Sinha, G. T. Bereznai: Optimum approximation on high-order systems by low-order models. Internat. J. Control 14 (1971), 5, 951-959.

[5] M. Milanese, A. Negro: Uniform approximation of systems: a Banach space approach. J. Optim. Theory Appl. 12 (1973), 2, 203-217. MR 0346549 | Zbl 0247.93003

[6] J. D. Aplevich: Approximation of discrete linear systems. Internat. J. Control 17 (1973), 3, 565-575. Zbl 0253.93022

[7] J. B. Riggs, T. E. Edgar: Least-squares reduction of linear systems using impulse response. Internat. J. Control 20 (1974), 2, 213-223. Zbl 0285.49009

[8] R. Genesio, R. Rome: Identification of reduced models from noisy data. Internat. J. Control 21 (1975), 2, 203-211. MR 0368882

[9] S. A. Arafeh, A. P. Sage: Multilevel discrete time system identification in large scale systems. Internat. J. Systems Sci. 15 (1974), 8, 753-791. MR 0351530 | Zbl 0286.93003

[10] M. G. Singh: Multi-level state estimation. Internat. J. Systems Sci. 6 (1975), 6, 535-555. MR 0373726 | Zbl 0302.93028

[11] Z. Bubnicki, L. Koszałka: Introductory Concept of Experiment Control. Technical Report No. 68, Institute of Eng. Cybernet., Technical University of Wroclaw, Wroclaw 1974.

[12] Z. Bubnicki: On the multistage identification. Systems Sci. 3 (1977), 2, 207-210. MR 0688164 | Zbl 0368.93024

[13] J. Swiątek: On two-stage parameter estimation in static systems. IEEE Trans. Systems Man Cybernet. 13 (1983), 1, 77-81.

[14] R. N. Pandya, B. Pagurek: Two stage least-squares estimators and their recursive approximations. In: Proc. 3rd IFAC Symp. Identification and System Parameter Estimation (1973), 701-710. Zbl 0317.62071

[15] R. N. Pandya: A class of bootstrap estimators and their relationship to the generalized two stage least-squares estimators. IEEE Trans. Automat. Control -AC-19 (1974), 6, 831-835. Zbl 0291.93061

[16] R. M. Prasad A. K. Sinha, A. K. Mahalanabis: Two-stage identification on closed-loop systems. IEEE Trans. Automat. Control AC-22 (1977), 6, 987-988.

[17] S. Y. Fakhouri: Identification of a class of non-linear systems from short input/output records. Internat. J. Systems Sci. 11 (1980), 11, 1327-1334. MR 0574072 | Zbl 0456.93055

[18] E. Rafajłowicz: Decomposition of the least-squares identification algorithm on the basis of a two-stage experiment. Systems Sci. 7 (1981), 1, 105-109.

[19] T. C. Hsia: A two-stage least-squares procedure for system identification. IEEE Trans. Automat. Control AC-26 (1981), 3, 742-745. MR 0630811 | Zbl 0481.93060

[20] J. M. Mendel: Multistage least-squares parameter estimation: an approach to modelling large scale systems. Presented at the 5th Symp. Nonlinear Estimation and its Applications, San Diego 1974.

[21] J. M. Mendel: Computation requirements for multistage least-squares estimators. Presented at the 6th Symp. Nonlinear Estimation and its Applications, San Diego 1975.

[22] J. M. Mendel: Multistage least-squares parameter estimators. IEEE Trans. Automat. Control AC-20 (1975), 6, 775-782. MR 0398634 | Zbl 0318.62052

[23] K. Yosida: Functional Analysis. Springer-Verlag, Berlin 1980. MR 0617913 | Zbl 0435.46002

[24] K. Maurin: Methods of Hilbert Spaces. Polish Scientific Publishers, Warsaw 1972. MR 0407618