Lie–Bäcklund symmetry, reduction, and solutions of nonlinear evolutionary equations / W. RZESZUT, I. M. TSYFRA, V. A. VLADIMIROV // Ukrainian Mathematical Journal ; ISSN 0041-5995. — 2022 vol. 74 no. 3, s. 385–394. — Bibliogr. s. 394, Abstr.. — Wersja w jęz. ukraińskim dostępna w: {https://umj.imath.kiev.ua/index.php/umj/article/view/7007} [2022-11-17]. — I. M. Tsyfra - dod. afiliacja: Subbotin Institute of Geophysics, National Academy of Sciences of Ukraine, Kyiv, Ukraine. — tekst: https://link.springer.com/content/pdf/10.1007/s11253-022-02070-w.pdf

On classical symmetries of ordinary differential equations related to stationary integrable partial differential equations / Ivan TSYFRA // Opuscula Mathematica ; ISSN 1232-9274. — Tytuł poprz.: Scientific Bulletins of Stanisław Staszic Academy of Mining and Metallurgy. Opuscula Mathematica. — 2021 vol. 41 no. 5, s. 685–699. — Bibliogr. s. 699, Abstr.. — tekst: https://www.opuscula.agh.edu.pl/vol41/5/art/opuscula_math_4133.pdf

On reducing and finding solutions of nonlinear evolutionary equations via generalized symmetry of ordinary differential equations / Ivan TSYFRA, Wojciech RZESZUT // Mathematical Biosciences and Engineering ; ISSN 1547-1063. — 2022 vol. 19 iss. 7 spec. iss.: Applications of differential equations in Mathematical Biosciences and Engineering, s. 6962–6984. — Bibliogr. s. 6982–6984, Abstr.. — Publikacja dostępna online od: 2022-05-10. — tekst: http://www.aimspress.com/article/doi/10.3934/mbe.2022328

Symmetry and solution of neutron transport equations in nonhomogeneous media / Ivan TSYFRA, Tomasz Czyżycki // Abstract and Applied Analysis ; ISSN 1085-3375. — 2014 art. no. 724238, s. [1–9]. — Bibliogr. s. [9]. — tekst: http://downloads.hindawi.com/journals/aaa/2014/724238.pdf