1. Abiteboul S., Buneman P., Suciu D. (1999) Data on the Web: From Relations to Semistructured Data and XML. Morgan Kaufmann, San Francisco CA
2. Berlea A., Seidl H.: Binary queries. Extreme Markup Languages (2002)
3. Brown A., Fuchs M., Robie J., Wadler P. MSL: A model for W3C XML Schema. WWW 10 (2001)
4. Cardelli L., Gordon A. (2000) Anytime, anywhere: Modal logic for mobile ambients Principles of Programming Languages (POPL). ACM Press, New York
5. Cardelli L., Ghelli G.: A query language based on the ambient logic. In: European Symposium on Programming (ESOP), LNCS vol. 2028, pp. 1–22. Springer, Berlin Heidelberg New York (2001)