Reference:

Harri Jäppinen, Timo Honkela, Aarno Lehtola, and Kari Valkonen. Hierarchical natural language database interface system. In R. Trappl, editor, Proceedings of the 9th European Meeting on Cybernetics and Systems Research, pages 893–900. Kluwer Academic Publishers, 1998.

Suggested BibTeX entry:

@inproceedings{Cybernetics98,
    author = {Harri J{\"a}ppinen and Timo Honkela and Aarno Lehtola and Kari Valkonen},
    booktitle = {Proceedings of the 9th European Meeting on Cybernetics and Systems Research},
    editor = {Trappl, R.},
    pages = {893-900},
    publisher = {Kluwer Academic Publishers},
    title = {Hierarchical Natural Language Database Interface System},
    year = {1998},
}