Implementing a Query Language for Java Object Database. - Emil Wcislo; Piotr Habela; Kazimierz Subieta (ADBIS, 2012)

Handling XML and Relational Data Sources with a Uniform Object-Oriented Query Language. - Emil Wcislo; Piotr Habela; Kazimierz Subieta (Intelligent Tools for Building a Scientific Information Platform, 2013)