SpringerLink (Online service), Vckovski, A., Brassel, K. E., & Schek, H. (1999). Interoperating Geographic Information Systems: Second International Conference, INTEROP'99, Zurich, Switzerland, March 10-12, 1999 Proceedings (1st ed. 1999.). Springer Berlin Heidelberg : Imprint: Springer. https://doi.org/10.1007/10703121
Παραπομπή σε μορφή Chicago (17η εκδ.)SpringerLink (Online service), Andrej Vckovski, Kurt E. Brassel, και Hans-Jörg Schek. Interoperating Geographic Information Systems: Second International Conference, INTEROP'99, Zurich, Switzerland, March 10-12, 1999 Proceedings. 1st ed. 1999. Berlin, Heidelberg: Springer Berlin Heidelberg : Imprint: Springer, 1999. https://doi.org/10.1007/10703121.
Παραπομπή σε μορφή MLA (8th εκδ.)SpringerLink (Online service), et al. Interoperating Geographic Information Systems: Second International Conference, INTEROP'99, Zurich, Switzerland, March 10-12, 1999 Proceedings. 1st ed. 1999. Springer Berlin Heidelberg : Imprint: Springer, 1999. https://doi.org/10.1007/10703121.
