A semi-strong perfect digraph theorem. - Stephan Dominique Andres; Helena Bergold; Winfried Hochstättler; Johanna Wiehe (AKCE Int. J. Graphs Comb., 2020)

The NL-flow polynomial. - Barbara Altenbokum; Winfried Hochstättler; Johanna Wiehe (Discret. Appl. Math., 2021)