K. Scharnhorst: Angles in complex vector spaces. Acta Applicandae Mathematicae 69(2001)95-103 [math.HO/9904077] (DOI: 10.1023/A:1012692601098). [SPIRES record]
Abstract: The article reviews some of the (fairly scattered) information available in the mathematical literature on the subject of angles in complex vector spaces. The following angles and their relations are considered: Euclidean, complex, and Hermitian angles, (Kasner's) pseudo-angle, the Kähler angle (synonyms for the latter used in the literature are: angle of inclination, characteristic deviation, holomorphic deviation, holomorphy angle, Wirtinger angle, slant angle).