1. Agrachev, A. A. and Gamkrelidze, R. V.: Exponential representation of flows and chronological calculus,Mat. Sb. 107 (1978), 467?532 (Russian).
2. Agrachev, A. A., Gamkrelidze, R. V. and Sarychev, A. V.: Local invariants of smooth control systems,Acta Appl. Math. 14 (1989), 191?237.
3. Agrachev, A. A. and Gamkrelidze, R. V.: Volterra series and groups of substitutions,Itogi Nauki. Sovremen. Probl. Mat. Nov. Dost. 39 (1991), VINITI, Moscow, 3?40 (Russian).
4. Agrachev, A. A. and Gamkrelidze, R. V.: Local controllability for families of diffeomorphisms,Systems Control Lett. 20 (1993), 67?76.
5. Agrachev, A. A. and Gamkrelidze, R. V: inL. Markus Festschrift, Marcel Dekker, 1993 (to appear).