Mladenov, Ivaïlo M. (ed.) et al., Proceedings of the 21st international conference on geometry, integrability and quantization, Varna, Bulgaria, June 3–8, 2019. Sofia: Avangard Prima; Sofia: Bulgarian Academy of Sciences, Institute of Biophysics and Biomedical Engineering. Geom. Integrability Quantization 21, 320-327 (2020).
Dobrev, Vladimir (ed.), Quantum theory and symmetries with Lie theory and its applications in physics. Volume 2. QTS-X/LT-XII, Varna, Bulgaria, June 19–25, 2017. Singapore: Springer (ISBN 978-981-13-2178-8/hbk; 978-981-13-2179-5/ebook). Springer Proceedings in Mathematics & Statistics 255, 217-231 (2018).
Nikitin, A. G. (ed.) et al., Proceedings of the fourth international conference on symmetry in nonlinear mathematical physics, Kyïv, Ukraine, July 9–15, 2001. Part 1. Dedicated to the 200th anniversary of M. Ostrohrads’kyi. Kyïv: Institute of Mathematics of NAS of Ukraine (ISBN 966-02-2486-9). Proc. Inst. Math. Natl. Acad. Sci. Ukr., Math. Appl. 43(1), 162-166 (2002).
Bao, Gang (ed.) et al., Mathematical modeling in optical science. Proceedings of a minisymposium on optics at SIAM’s annual meeting, Stanford Univ., Palo Alto, CA, USA, 1997. Philadelphia, PA: SIAM. Front. Appl. Math. 179-206 (2001).
Mladenov, I. M. (ed.) et al., Proceedings of the international conference on geometry, integrability and quantization, Varna, Bulgaria, September 1-10, 1999. Sofia: Coral Press Scientific Publishing. 55-77 (2000).
Shkil, Mykola (ed.) et al., Symmetry in nonlinear mathematical physics. Proceedings of the second international conference, Kyiv, Ukraine, July 7-13, 1997. Memorial Prof. W. Fushchych conference. Vol. 2. Kyiv: Institute of Mathematics of the National Academy of Sciences of Ukraine. 307-312 (1997).
Shkil, Mykola (ed.) et al., Symmetry in nonlinear mathematical physics. Proceedings of the second international conference, Kyiv, Ukraine, July 7-13, 1997. Memorial Prof. W. Fushchych conference. Vol. 1. Kyiv: Institute of Mathematics of the National Academy of Sciences of Ukraine. 214-216 (1997).