Sergei Petropavlovskii Petropavlovsky, S., Tsynkov, S., & Turkel, E. (2018). A method of boundary equations for unsteady hyperbolic problems in 3D. Journal of Computational Physics, 365, 294–323. https://doi.org/10.1016/j.jcp.2018.03.039 Magura, S., Petropavlovsky, S., Tsynkov, S., & Turkel, E. (2017). High-order numerical solution of the Helmholtz equation for domains with reentrant corners. Applied Numerical Mathematics, 118, 87–116. https://doi.org/10.1016/j.apnum.2017.02.013