SpringerLink (Online service), Hehl, F. W., Kiefer, C., & Metzler, R. J. (1998). Black Holes: Theory and Observation: Proceedings of the 179th W.E. Heraeus Seminar Held at Bad Honnef, Germany, 18-22 August 1997 (1st ed. 1998.). Springer Berlin Heidelberg : Imprint: Springer. https://doi.org/10.1007/b13593
Παραπομπή σε μορφή Chicago (17η εκδ.)SpringerLink (Online service), Friedrich W. Hehl, Claus Kiefer, και Ralph J.K Metzler. Black Holes: Theory and Observation: Proceedings of the 179th W.E. Heraeus Seminar Held at Bad Honnef, Germany, 18-22 August 1997. 1st ed. 1998. Berlin, Heidelberg: Springer Berlin Heidelberg : Imprint: Springer, 1998. https://doi.org/10.1007/b13593.
Παραπομπή σε μορφή MLA (8th εκδ.)SpringerLink (Online service), et al. Black Holes: Theory and Observation: Proceedings of the 179th W.E. Heraeus Seminar Held at Bad Honnef, Germany, 18-22 August 1997. 1st ed. 1998. Springer Berlin Heidelberg : Imprint: Springer, 1998. https://doi.org/10.1007/b13593.
