Open Source vs. Closed Source Software: Towards Measuring Security
G. Schryen, R. Kadura, in: 24th Annual ACM Symposium on Applied Computing, 2009.

A comprehensive and comparative analysis of the patching behavior of open source and closed source software vendors
G. Schryen, in: 5th International Conference on IT Security Incident Management \'26; IT Forensics, 2009.

Security of open source and closed source software: An empirical comparison of published vulnerabilities
G. Schryen, in: 15th Americas Conference on Information Systems, 2009.

Effektivität und Effizienz von Anti-Spam-Maßnahmen
G. Schryen, Linux Technical Review (2008).

Practical Security of Large-scale Elections: An Exploratory Case Study of Internet Voting in Estonia
G. Schryen, in: 7th Workshop on E-Business (WEB 2008, AIS Special Interest Group on E-Business), 2008.

Preventing E-mail Spam: The Conceptualization and the Analysis of an Infrastructure Framework
G. Schryen, Preventing E-Mail Spam: The Conceptualization and the Analysis of an Infrastructure Framework, 2007.

A Scalable and Flexible Infrastructure Framework For Addressing Spam
G. Schryen, in: D. Satesh, R. Prabhakar (Eds.), Proceedings of IPSI International Conference on Advances in the Internet, Processing, Systems, and Interdisciplinary Research, ICFAI University Press, Hyderabad, India, 2007, pp. 55–64.

Anti-Spam Measures: Analysis and Design
G. Schryen, Anti-Spam Measures: Analysis and Design, Springer, Berlin, Heidelberg, New York, 2007.

Anti-spam legislation: An analysis of laws and their effectiveness
G. Schryen, Information and Communications Technology Law 16 (2007) 17–32.

Approaches Addressing Spam
G. Schryen, in: D. Satesh, R. Prabhakar (Eds.), Spam: An Introduction, ICFAI University Press, Hyderabad, India, 2007, pp. 41–57.

Armed for the spam battle - a technological and organizational infrastructure framework
G. Schryen, in: 40th Annual Hawaii International Conference on System Sciences, 2007.

Do anti-spam measures effectively cover the e-mail communication network? A formal approach
G. Schryen, The Journal of Information Systems Security (AIS Special Interest Group in Security) 3 (2007) 66–90.

Location Based Services
G. Schryen, in: H. Schulte (Ed.), Vom LAN Zum Kommunikationsnetz - Systeme Und Applikationen, Interest-Verlag, Kissing, 2007.

Spam-Emails
G. Schryen, in: H. Schulte (Ed.), Vom LAN Zum Kommunikationsnetz - Systeme Und Applikationen, Edition 02/2007, Interest-Verlag, Kissing, 2007.

The Impact that Placing Email Addresses on the Internet has on the Receipt of Spam ? An Empirical Analysis
G. Schryen, Computers &; Security 2 (2007) 361–372.

A formal approach towards assessing the effectiveness of anti-spam procedures
G. Schryen, in: 39th Annual Hawaii International Conference on System Sciences, 2006.

A honeypot for the exploration of spammers' behaviour
G. Schryen, IATAC IAnewsletter 8 (2005) 22–25.

An e-mail honeypot addressing spammers' behavior in collecting and applying addresses
G. Schryen, in: Proceedings of the 6th IEEE Information Assurance Workshop, Westpoint, 2005, pp. 37–41.

Security Aspects of Internet Voting
G. Schryen, in: 37th Annual Hawaii International Conference on System Sciences, 2004.

Effektivität von Lösungsansätzen zur Bekämpfung von Spam
G. Schryen, Wirtschaftsinformatik 46 (2004) 281–288.

Fighting Spam: Motivating an Account-based Approach
G. Schryen, in: P. Isaias (Ed.), Proceedings of the IADIS International Conference WWW/Internet 2004. Vol. 2, IADIS Press, Madrid, 2004, pp. 937–940.

How Security Problems Can Compromise Remote Internet Voting Systems
G. Schryen, in: Workshop of the ESF TED Programme, 2004, pp. 121–131.

Neulich am Hotspot - Bringt Mobiles Internet die Menschen ins Netz?
G. Schryen, in: G. Gehrke (Ed.), Digitale Teilung - Digitale Integrationf: Perspektiven Der Internetnutzung, KOPAED-Verlag, München, 2004, pp. 45–51.

Online Marktforschung im Mittelstand: Analyse von Konsumentenverhalten in 3D-Internet-Welten
G. Schryen, J. Herstell, M. Schoenen, Online Marktforschung Im Mittelstand: Analyse von Konsumentenverhalten in 3D-Internet-Welten, Deutscher Universitäts-Verlag, Wiesbaden, 2003.

Online-Marktforschung - Analyse von Konsumentenverhalten in virtuellen Umgebungen, in: Information Management & Consulting, 18,2
G. Schryen, J. Herstell, IMf: Die Zeitschrift Für Information Management Und Consulting 18 (2003) 74–77.

E-Democracy: Internet Voting
G. Schryen, in: Proceedings of the IADIS International Conference WWW Internet 2003. Vol. 2, IADIS Press, Algarve, 2003, pp. 1017–1021.

Internet-Wahlen
G. Schryen, in: 6. Internationale Tagung Wirtschaftsinformatik, 2003, pp. 937–956.

Data Warehouse in der Marktforschung - Analyse von Benutzeraktivitäten in virtuellen Welten
G. Schryen, M. Schoenen, in: Data Warehousing 2002, 2002, pp. 103–119.

Elektronisches Papier - Display-Technologie mit weitem Anwendungsspektrum
G. Schryen, J. Karla, Wirtschaftsinformatik 44 (2002) 567–574.

Elektronische Zeitung - das Erbe Gutenbergs?
G. Schryen, I-Com. Zeitschrift Für Interaktive Und Kooperative Medien (2002) 36–37.

Komponentenorientierte Softwareentwicklung in Softwareunternehmen: Konzeption eines Vorgehensmodells zur Einführung und Etablierung
G. Schryen, Komponentenorientierte Softwareentwicklung in Softwareunternehmen: Konzeption Eines Vorgehensmodells Zur Einführung Und Etablierung, Deutscher Universitäts-Verlag, Wiesbaden, 2001.