1. A. A. Ageev, A. E. Baburin, and E. Kh. Gimadi, “A 3/4-Approximation Algorithm for Finding Two Disjoint Hamiltonian Cycles of Maximum Weight,” Diskret. Anal. Issled. Oper. Ser 1, 13(2), 11–20 (2006) [J. Appl. Indust. Math. 1 (2), 142–147 (2007)].
2. E. Kh. Gimadi, Yu. V. Glazkov, and A. N. Glebov, “Approximation Algorithms for Solving the 2-Peripatetic Salesmen Problem on a Complete Graph with Edge Weights 1 and 2,” Diskret. Anal. Issled. Oper. Ser 2, 14(2), 41–61 (2007) [J. Appl. Indust. Math. 3 (1), 46–60 (2009)].
3. A. I. Serdyukov, “An Algorithm with an Estimate for a Salesman Problem forMaximum,” in Proceedings of the Institute of Mathematics: Controlled Systems, Vol. 25 (Inst. Mat., Novosibirsk, 1984), pp. 80–86.
4. Z.-Z. Chen, Y. Okamoto, and L. Wang, “Improved Deterministic Approximation Algorithms for Max TSP,” Inform. Process. Lett. 95(2), 333–342 (2005).
5. Z.-Z. Chen and L. Wang, “An Improved Randomized Approximation Algorithm for Max TSP,” J. Comb. Optim. 9(4), 401–432 (2005).