Nondifferentiable functions, Haar null sets and Wiener measure Petr Holický, Luděk Zajíček (2000) Acta Universitatis Carolinae. Mathematica et Physica
Nonwhere differentiable solutions of a system of functional equations. (Summary). Roland Girgensohn (1993) Aequationes mathematicae
Nowhere differentiable solutions of a system of functional equations. Roland Girgensohn (1994) Aequationes mathematicae