- Scientific assistant Martin Luther University, 1953-1963. Professor mathematics Ilmenau Institute of Technology University, Germany, 1963—1992. With German Army, 1944-1945.
- Spectra of Graphs: Theory and Application (Pure & Applied Mathematics)
- The theory of graph spectra can, in a way, be considered as an attempt to utilize linear algebra including, in particular, the well-developed theory of matrices for the purposes of graph theory and its applications.