A Synthetic Actor model for long-term computer games. - D. R. Silva; Clauirton de Albuquerque Siebra; J. L. Valadares; A. L. Almeida; Alejandro C. Frery; J. Rocha Falcão; Geber L. Ramalho (Virtual Real., 2000)

An Ongoing Assessment Model for Distance Learning. - D. R. Silva; Marina Teresa Pires Vieira (IMSA, 2001)