Advanced aviation concepts via simulation: research flight simulation of future autonomous aircraft operations. - Mario S. V. Valenti Clari; Rob C. J. Ruigrok; Bart W. M. Heesbeen; Jaap Groeneweg (WSC, 2002)

Designing for safety: the 'free flight' air traffic management concept. - Jacco M. Hoekstra; Ronald N. H. W. van Gent; Rob C. J. Ruigrok (Reliab. Eng. Syst. Saf., 2002)