SpringerLink (Online service), Goettl, B. P., Halff, H. M., Redfield, C. L., & Shute, V. J. (1998). Intelligent Tutoring Systems: 4th International Conference, ITS '98, San Antonio, Texas, USA, August 16-19, 1998, Proceedings (1st ed. 1998.). Springer Berlin Heidelberg : Imprint: Springer. https://doi.org/10.1007/3-540-68716-5
Παραπομπή σε μορφή Chicago (17η εκδ.)SpringerLink (Online service), Barry P. Goettl, Henry M. Halff, Carol L. Redfield, και Valerie J. Shute. Intelligent Tutoring Systems: 4th International Conference, ITS '98, San Antonio, Texas, USA, August 16-19, 1998, Proceedings. 1st ed. 1998. Berlin, Heidelberg: Springer Berlin Heidelberg : Imprint: Springer, 1998. https://doi.org/10.1007/3-540-68716-5.
Παραπομπή σε μορφή MLA (8th εκδ.)SpringerLink (Online service), et al. Intelligent Tutoring Systems: 4th International Conference, ITS '98, San Antonio, Texas, USA, August 16-19, 1998, Proceedings. 1st ed. 1998. Springer Berlin Heidelberg : Imprint: Springer, 1998. https://doi.org/10.1007/3-540-68716-5.
