1. T. Levi-Civita, “Sulle funzioni che ammettono una formula d’addizione del tipo $$f\left( {x + y} \right)\sum {\begin{array}{*{20}{c}} n \\ {i = 1} \end{array}} {X_i}\left( x \right){Y_i}\left( y \right)$$ f ( x + y ) ∑ n i = 1 X i ( x ) Y i ( y ) ,” Rom. Acc. L. Rend., 22:2 (1913), 181–183.
2. V. M. Buchstaber and D. V. Leikin, “Trilinear functional equations,” Uspekhi Mat. Nauk, 60:2(362) (2005), 151–152; English transl.: Russian Math. Surveys, 60:2 (2005), 341–343.
3. V. M. Buchstaber and D. V. Leikin, “Addition laws on Jacobian varieties of plane algebraic curves,” in: Nonlinear Dynamics, Collection of papers, Trudy Mat. Inst. Steklova, vol. 251, Nauka, Moscow, 2005, 54–126; English transl.: Proc. Steklov Inst. Math., 251 (2005), 49–120.
4. V. M. Buchstaber and I. M. Krichever, “Integrable equations, addition theorems, and the Riemann–Schottky problem,” Uspekhi Mat. Nauk, 61:1(367) (2006), 25–84; English transl.: Russian Math. Surveys, 61:1 (2006), 19–78.
5. M. Bonk, “The addition theorem of Weierstrass’s sigma function,” Math. Ann., 298:4 (1994), 591–610.