1. Ruiz, J.C., Valderrama, M.J., and Gutiérrez, R. (1995). Kalman Filtering on Approximative State Space Models. Journal of Optimization Theory and Applications, 84(2), 415–431.
2. Valderrama, M.J., Aguilera, A.M. and Ocaña, F.A. (2000). Predicción
Dinámica mediante Análisis de Datos Funcionales. Hespérides-La Muralla, Madrid.
3. Valderrama, M.J., Aguilera, A.M. and Ruiz, J.C. (1998). Time Series Forecasting by Principal Component Methods. In: COMPSTAT98 Proceedings in Computational Statistics, 137–146. Heidelberg: Physica-Verlag.