SpringerLink (Online service), Chen, P. P., Akoka, J., Kangassalu, H., & Thalheim, B. (1999). Conceptual Modeling: Current Issues and Future Directions (1st ed. 1999.). Springer Berlin Heidelberg : Imprint: Springer. https://doi.org/10.1007/3-540-48854-5
Παραπομπή σε μορφή Chicago (17η εκδ.)SpringerLink (Online service), Peter P. Chen, Jacky Akoka, Hannu Kangassalu, και Bernhard Thalheim. Conceptual Modeling: Current Issues and Future Directions. 1st ed. 1999. Berlin, Heidelberg: Springer Berlin Heidelberg : Imprint: Springer, 1999. https://doi.org/10.1007/3-540-48854-5.
Παραπομπή σε μορφή MLA (8th εκδ.)SpringerLink (Online service), et al. Conceptual Modeling: Current Issues and Future Directions. 1st ed. 1999. Springer Berlin Heidelberg : Imprint: Springer, 1999. https://doi.org/10.1007/3-540-48854-5.
