How to Implement a Naturalistic Model of Abstracting: Four Core Working Steps of an Expert Abstractor. - Brigitte Endres-Niggemeyer; E. Maier; Alexander Sigel (Inf. Process. Manag., 1995)

Einfürung in wissenorganisatorische Aspekte bei der Nutzung und Bereitstellung fachlicher Internet-Resourcen. - H. Peter Ohly; Alexander Sigel (Herausforderungen an die Wissensorganisation (ISKO Tagung), 1997)

Long-Term Value Adding in an Open Category Network: An Informal Social Approach Towards Relating Conceptual Order Systems on the Internet. - Alexander Sigel (ISI, 1998)

Report on the Open Space Sessions. - Alexander Sigel (TMRA, 2005)

Topic Maps-Based Semblogging with semblog-tm. - Alexander Sigel; Lars Bünten; Marcus Frank (TMRA, 2006)

Topic-Oriented Portals. - Alexander Sigel; Khalil Ahmed (Encyclopedia of Portal Technologies and Applications, 2007)