IT Project Portfolio Assessment criteria: development and validation of a reference model. - Ruud Wissenburg; Rob J. Kusters; Harry Martin; Joyce Evers-Wagemakers (CBI (1), 2022)

IT Project Portfolio Management: Development and Validation of a Reference Model. - Ruud Wissenburg; Rob J. Kusters; Harry Martin (ICEIS (1), 2023)

Relationships between IT Project Portfolio risk and IT Project Portfolio health. - Ruud Wissenburg; Rob J. Kusters; Harry Martin (CBI, 2023)