His primary interest was in the theory of characteristic functions.

The twentieth century saw several waves of interest in special function theory.

This operation provides the theory of functions with its most powerful structure.

He worked on the theory of functions and in mathematical physics.

He has to his credit more than 90 research articles in complex function theory and Multimedia.

Then the function theory is enriched by sequences and series.

He conducted research in the field of theory of functions.

Riemann's dissertation on the theory of functions appeared in 1851.

Have you ever looked into the early history of the theory of elliptic functions?

His first book "The theory of functions of a complex variable" was published in 1935.