B2 Non-refereed book chapter or chapter in a compilation book

Two problems on commutation of languages

Authors: Karhumäki Juhani, Petre Ion

Editors: Paun Gheorghe, Rozenberg Grzegorz, Salomaa Arto

Publication year: 2004

Book title : Current trends in Theoretical Computer Science (The Challenge of the New Century)

First page : 477

Last page: 494