Oja, E. (1982). "A Simplified Neuron Model As a Principal
Component Analyzer," *Journal of Mathematical Biology*, **15**,
267-273.

Oja, E. (1983). *Subspace Methods of Pattern Recognition*.
Research Studies Press and John Wiley. Letchworth, England.

Oja, E. (1989). "Neural Networks, Principal Components,
and Subspaces," *International Journal of Neural Systems*, **1**(1),
61-68.

Oja, E. (1991). "Data Compression, Feature Extraction,
and Autoassociation in Feedforward Neural Networks," *Artificial
Neural Networks, Proceedings of the 1991 International Conference on Artificial
Neural Networks* (Espoo 1991), T. Kohonen, K. Mäkisara, O. Simula,
and J. Kangas, Editors, vol. I, 737-745. Elsevier Science Publishers B.
V., Amsterdam.

Oja, E. and Karhunen, J. (1985). "On Stochastic Approximation
of the Eigenvectors of the Expectation of a Random Matrix," *Journal
of Mathematical Analysis and Applications*, **106**, 69-84.

Okajima, K., Tanaka, S., and Fujiwara, S. (1987). "A
Heteroassociative Memory Network with Feedback Connection," in *Proc.
IEEE First International Conference on Neural Networks* (San Diego 1987),
M. Caudill & C. Butler, Editors, vol. II, 711-718.