Koch, M. “Nonlinear Inversion of Local Seismic Travel Times for the Simultaneous Determination of the 3D-Velocity Structure and Hypocentres - Application to the Seismic Zone Vrancea”. Journal of Geophysics 56, no. 1 (February 27, 1986): 160-173. Accessed October 4, 2025. https://journal.geophysicsjournal.com/JofG/article/view/240.