We are proud that the authors of the following textbooks use and recommend f(z).
Complex Variables and Applications - Sixth Edition
by Brown and Churchill
McGraw-Hill
Complex Variables With Applications - Second Edition
by A. David Wunsch
Addison Wesley and Benjamin Cummings
Complex Analysis: for Mathematics and Engineering - Third Edition
by John H. Mathews and Russell W. Howell
Jones & Bartlett Pub. Inc
by Tristan Needham
Oxford University Press