T. . Körpinar and R. C. . Demirkol, “Curvature and torsion dependent energy of elastica and nonelastica for a lightlike curve in the Minkowski space”, Ukr. Mat. Zhurn., vol. 72, no. 8, pp. 1095–1105, Aug. 2020, doi: 10.37863/umzh.v72i8.847.