[1] CHRASTINA J.: Exаmples from the Cаlculus of vаriаtions I, II; III, IV. Math. Bohemica 125; 126 (2000; 2001), 55-76, 187-197; 93-111, 691-710.

[2] CHRASTINOVÁ V.: Underdetermined differentiаl equаtions. In: Theory and practice of differential equations. Proc. of the Зrd Internat. Conference "Diffeгential equations and applications" Saint-Petersburg, Russia, June 12-17, 2000. Math. Res., St. Petersburg 6, Izd. Sankt-Peterburgskogo Gos. Tekhn. Univ., Sankt-Peterburg, 2000, pp. 52-57. MR 1826232

[3] CHRASTINOVÁ V.-TRYHUK V.: On the Mаyer problem. I. Generаl principles. Math. Slovaca 52, 555-570.

[4] PELLETIER F.-VALÉRE BOUCHE L.: Abnormаlity of trаjectory in sub-Riemаnniаn structure. In: Geometry in Nonlinear Control and Differential Inclusions. Banach Center Publ. 32, Polish Acad. Sci., Warszaw, 1995, pp. 301-317. MR 1364436

[5] SUSSMANN H. J.: A Cornucopiа of four-dimensionаl аbnormаl sub-Riemаnniаn minimizers. In: Sub-Riemannian Geometry (A. Bellaďche et al., eds.), Proc. of the Satellite Meeting of the lst European Congress of Mathematics "Journées nonholonomes: géométrie sous-riemannienne, théorie du contrôle, robotique", Paris, France, June 30-July 1, 1992. Progr. Math. 144, Birkhäuser, Basel, 1996, pp. 341-364. MR 1421825