1. Bryuno, A.D. (often transliterated as Bruno or Brjuno), Analytical forms of differential equations, I, II, Trudy Mosk. Mat. Ob. 25 (1971), 119–262;
2. Bryuno, A.D. (often transliterated as Bruno or Brjuno), Analytical forms of differential equations, I, II, Trudy Mosk. Mat. Ob. 26 (1972), 199–239;
3. Bryuno, A.D. English translation in Trans. Mosc. Math. Soc. 25 (1971);
4. Bryuno, A.D. English translation in Trans. Mosc. Math. Soc. 26 (1972).
5. Chicone, C., “Finiteness theorems for limit cycles”, Book review, Bull. Amer. Math. Soc. 28, no. 1 (1993), 123–130.