1. Frew, A.J. and E. Crichton, User Interfaces in Information and Reservation Systems: Classification and Development Issues, in Information and Communications Technologies in Tourism, D. Buhalis and W. Schertler, Editors. 1999, Springer-Verlag: Vienna, Austria. p. 328–336.
2. O’Connor, P., Electronic Information Distribution in Tourism and Hospitality. 1999: CAB International.
3. Preece, L et. al., Human Computer Interaction. 1994, London: Addison Wesley.
4. Chi, H.U., formal Specification of User Interfaces: A Comparison and Evaluation of Four Axiomatic Approaches. IEEE Transactions on Software Engineering, 1985. 11(8): p. 671–685
5. Johnson, P., Task Analysis and Software Engineering. 1992: McGraw-Hill.