How to detect a counterfeit coin: Adaptive versus non-adaptive solutions. - Axel Born; Cor A. J. Hurkens; Gerhard J. Woeginger (Inf. Process. Lett., 2003)

The Freudenthal Problem and its Ramifications (Part I). - Axel Born; Cor A. J. Hurkens; Gerhard J. Woeginger (Bull. EATCS, 2006)

The Freudenthal Problem and its Ramifications (Part II). - Axel Born; Cor A. J. Hurkens; Gerhard J. Woeginger (Bull. EATCS, 2007)

The Freudenthal Problem and its Ramifications (Part III). - Axel Born; Cor A. J. Hurkens; Gerhard J. Woeginger (Bull. EATCS, 2008)