A regularity theorem for harmonic mappings. Atsushi Tachikawa — 1987 Journal für die reine und angewandte Mathematik
Rotationally Symmetric Harmonic Maps from a Ball into a Warped Product Manifold. Atsushi Tachikawa — 1985 Manuscripta mathematica
On Interior regularity and Liouville's theorem for harmonic mappings. Atsushi Tachikawa — 1983 Manuscripta mathematica
Harmonic maps from a Riemannian manifold with a pole into an Hadamard manifold with negative sectional curvatures. Atsushi Tachikawa — 1992 Manuscripta mathematica
Partial regularity results up to the boundary for harmonic maps into a Finsler manifold Atsushi Tachikawa — 2009 Annales de l'I.H.P. Analyse non linéaire