no. S4
Ergodic Properties of a Complex Continued Fraction Transformation
Publications mathématiques et informatique de Rennes, no. S4 (1975), article no. 23, 2 p. 
@article{PSMIR_1975___S4_A23_0,
     author = {Shiokawa, Iekata},
     title = {Ergodic Properties of a Complex Continued Fraction Transformation},
     journal = {Publications math\'ematiques et informatique de Rennes},
     eid = {23},
     publisher = {D\'epartement de Math\'ematiques et Informatique, Universit\'e de Rennes},
     number = {S4},
     year = {1975},
     language = {en},
     url = {www.numdam.org/item/PSMIR_1975___S4_A23_0/}
}
Shiokawa, Iekata. Ergodic Properties of a Complex Continued Fraction Transformation. Publications mathématiques et informatique de Rennes, no. S4 (1975), article  no. 23, 2 p. http://www.numdam.org/item/PSMIR_1975___S4_A23_0/

[1] R. Kaneiwa, I. Shiokawa and J. Tamura, A proof of Perron’s theorem on Diophantine approximation in Eisenstein’s field 𝒬(-3), to appear.

[2] O. Perron, Uber einen Approximationssatz von Hurwitz und uber die Approximation einen Komplexen Zahl durch Zahlen des Korpers der dritten Einheitswurzeln, Sitz. d. Bayer (1931), 129-154. | JFM 57.0241.01 | Zbl 0004.24503