The negative tetrahedron and the first infinite family of connected digraphs that are strongly determined by the Hermitian spectrum. - Pepijn Wissing; Edwin R. van Dam (J. Comb. Theory A, 2020)

Self-converse mixed graphs are extremely rare. - Pepijn Wissing (Discret. Math., 2022)

Unit gain graphs with two distinct eigenvalues and systems of lines in complex space. - Pepijn Wissing; Edwin R. van Dam (Discret. Math., 2022)

Spectral fundamentals and characterizations of signed directed graphs. - Pepijn Wissing; Edwin R. van Dam (J. Comb. Theory A, 2022)