Internet accounting. - Aiko Pras; Bert-Jan van Beijnum; Ron A. M. Sprenkels; Róbert Párhonyi (IEEE Commun. Mag., 2001)

An interconnection architecture for micropayment systems. - Róbert Párhonyi; Dick A. C. Quartel; Aiko Pras; Lambert J. M. Nieuwenhuis (ICEC, 2005)

Second generation micropayment systems: lessons learned. - Róbert Párhonyi; Lambert J. M. Nieuwenhuis; Aiko Pras (I3E, 2005)

Micro payment gateways. - Róbert Párhonyi (2005)

Micropayment Systems. - Róbert Párhonyi (Handbook of Financial Cryptography and Security, 2010)