1. Euler, L., Methodus inveniendi lineas curvas maximi minimive proprietate gaudentes, sive solutio problematis isoperimitrici latissimo sensu accepti, Lausanne: Bousquet, 1744.
2. Sachkov, Yu.L., Optimality of Euler’s Elasticae, Dokl. Ross. Akad. Nauk, 2007, vol. 417, no. 1, pp. 23–25.
3. Sachkov, Yu.L., Controllability and Optimal Control for Invariant Systems on Lie Groups and Homogeneous Spaces, Doctoral (Phys.-Math.) Dissertation, Moscow: Inst. Mat., Ross. Akad. Nauk, 2008.
4. Sachkov, Yu.L., Maxwell Strata in Euler’s Elastic Problem, J. Dynam. Control Syst., 2008, vol. 14, no. 2, pp. 169–234.
5. Sachkov, Yu.L., Conjugate Points in Euler’s Elastic Problem, J. Dynam. Control Syst., 2008, vol. 14, no. 3, pp. 409–439.