K. Busawon, M. Farza, and H. Hammouri, A simple observer for a class of nonlinear systems, Applied Mathematics Letters, vol.11, issue.3, pp.27-31, 1998.
DOI : 10.1016/S0893-9659(98)00029-9

S. Chabraoui, D. Boutat, L. Boutat-baddas, and J. P. Barbot, Observability quadratic characteristic numbers, 42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475), 2001.
DOI : 10.1109/CDC.2003.1271716

J. P. Gauthier and I. Kupka, Deterministic observation theory and applications, 2001.
DOI : 10.1017/CBO9780511546648

M. Guay, Observer linearization by output diffeomorphism and output-dependent time-scale transformations, NOL- COS'01 Saint, pp.1443-1446, 2001.

H. Hammouri and J. P. Gauthier, Bilinearization up to the output injection, System and Control Letters, pp.139-149, 1988.

H. Hammouri and J. Morales, Observer synthesis for state-affine systems, 29th IEEE Conference on Decision and Control, 1990.
DOI : 10.1109/CDC.1990.203695

A. Isidori, Nonlinear control systems, 1989.

D. Luenberger, An introduction to observers, IEEE Transactions on Automatic Control, vol.16, issue.6, pp.596-602, 1971.
DOI : 10.1109/TAC.1971.1099826

W. Respondek, A. Pogromsky, and H. Nijmeijer, Time scaling for observer design with linearization error dynamics, IEEE Transactions on Automatic Control, vol.3, pp.199-216, 1989.

N. Kazantzis and C. Kravaris, Nonlinear observer design using Lyapunov's auxiliary theorem, Systems & Control Letters, pp.241-247, 1998.
DOI : 10.1109/cdc.1997.649779

A. Krener and A. Isidori, Linearization by output injection and nonlinear observers, Systems & Control Letters, pp.47-52, 1983.
DOI : 10.1016/0167-6911(83)90037-3

A. Krener and W. Respondek, Nonlinear observer with linearizable error dynamics in SIAM, J. Control and Optimization, vol.30, issue.6, pp.197-216, 1985.

A. Krener and M. Q. Xiao, Nonlinear observer design in the Siegel domain through, Proc of the 5th IFAC Symposium, pp.557-562, 2001.

X. H. Xia and W. B. Gao, Nonlinear Observer Design by Observer Error Linearization, SIAM Journal on Control and Optimization, vol.27, issue.1, pp.199-216, 1989.
DOI : 10.1137/0327011