Irna M. R. Evangelista Filha,  Alberto H. F. Laender,  Altigran Soares da Silva. 

This paper presents QSByE, an interface for querying semistructured data through examples. The interface supports QBE-like query operations that are based on the nested relational algebra, which has been extended to deal with common features found in semistructured data, such as nested and irregular structures. Therefore, QSByE is more suitable for casual users than tradicional query languages for semistructured data because it provides graphical facilities that assist the user on the query formulation process. QSByE operates over data repositories generated by DEByE, a tool for extracting data from Web sources.

http://www.cos.ufrj.br/wiiw/papers/21-Irna_Evangelista(16).pdf

Processando consulta.