Katsomallos M., Logothetidis F., Panagopoulou G., Sirmakessis S., Tsakalidis A. "Implementation of a Hidden Surface Removal Algorithm", 1st ALCOM Workshop, ALGORITHMS: Implementation, Libraries and Use, [http://www.mpi-sb.mpg.de/guide/staff/alcom/node67.html], 16 18 August 1993, Saarbruecken (Dagstuhl), Germany.
 Panagopoulou G., Sirmakessis S., Tsakalidis A., Vourdacha H. "Implementation of the kBB-tree", 1st ALCOM Workshop, ALGORITHMS: Implementation, Libraries and Use, [http://www.mpi-sb.mpg.de/guide/staff/alcom/node67.html], 16 18 August 1993, Saarbruecken (Dagstuhl), Germany.
 Chrisoulis C., Panagopoulou G., Sirmakessis S., Tsakalidis A., Tzimas J., "The PELICAN System", in the Workshop Proceedings of the 6th International Conference and Workshop on Database and Expert Systems Applications (DEXA 95), Springer Verlag, ISBN 3 901653 00 7, pp. 461 465, 4 8 September 1995, London, United Kingdom.
 Yiannis Moumtzidis, Spiros Sirmakessis, Giannis Tzimas, “Secure Interface for Risk Management Services”, in the proceedings of the Second International Workshop on User Interfaces to Data Intensive Systems, pp 96 100, Zurich, Switzerland, 31 May 1 June 2001.
 Konstantinos Markellos, Penelope Markellou, Giorgos Mavritsakis, Katerina Perdikuri, Spiros Sirmakessis, Athanasios Tsakalidis, “Mining patent databases for monitoring technological trends”, in the proceedings of the PANDA Workshop on Pattern Base Management Systems, April 10 2003, Como, Italy.
 Spiros Sirmakessis, “Mining for Gems of Information”, in the proceedings of the 1st International Workshop on Text Mining and its Applications, pp 1 6, Springer Verlag, April 5, 2003, Patras, Greece
 Maria Rigou, Spiros Sirmakessis, “Mining for Gems for Information”, in the proceedings of the 4th European Workshop on Image Analysis for Multimedia Interactive Services, pp 545 548, April 9-11, 2003, London, UK. (sponsored by IEEE)
 Athanasios Tsakalidis, Konstantinos Markellos, Katerina Perdikuri, Penelope Markellou, Spiros Sirmakessis, George Mayritsakis, “A multivariate analysis and visualization system for analysing patent data and producing technological and scientific indicators”, in the proceedings of the International workshop on Computational Management Science, Economics, Finance and Engineering, 28-30 March 2003, Limassol, Cyprus.
 Konstantinos Markellos, Penelope Markellou, Maria Rigou, Spiros Sirmakessis, “Web Mining: Past, Present and Future”, in the proceedings of the 1st International Workshop on Text Mining and its Applications, pp 25 35, Springer Verlag, April 5, 2003, Patras, Greece
 Penelope Markelou, Angeliki Panayiotaki, Spiros Sirmakessis, Athanasios Tsakalidis, “Using Hierarchy to Extract Innovation; The use of Patents in Clarifying Innovation”, to appear in the proceedings of the second International seminar on the Exchange of Technology and Know-how (ETK’ 2001) and the fourth NTTS seminar New Techniques and Technologies for Statistics,pp 881 882, Crete, Greece, 18 22 June 2001.
 L. Drossos, S. Sioutas, E. Sakkopoulos, S. Sirmakessis, “BDT-Grid: An Efficient Scalable Peer-to-peer Lookup System for Web Service Discovery”, in the proceedings of International Workshop on Peer to Peer and Service Oriented Hypermedia: Techniques and Systems (ACM HyperText 2005), 6 9 September 2005, Salzburg, Austria.
 Maria Rigou, Spiros Sirmakessis, Giannis Tzimas “Model Cloning: A Push to Reuse or a Disaster?”, in the proceedings of International Workshop on Adaptive and Personalized Semantic Web Peer (ACM HyperText 2005), 6 9 September 2005, Salzburg, Austria.
 Maria Rigou, Spiros Sirmakessis, Giannis Tzimas «A Method for Personalized Clustering in Data-Intensive Web Applications» in the Proceedings of the ACM Joint International Workshop on Adaptivity, Personalization and the Semantic Web at the 17th ACM Hypertext’06 conference, (http://www.ht06.org), 23-25 August, 2006, Odense, Denmark.
 Spiridoula Koukia, Maria Rigou, Spiros Sirmakessis “The Role of Content in m-Commerce and the Personalization Dimension” in the Proceedings of the ACM/IEEE/WI International Workshop on Adaptation and Personalization for e-Business Intelligence in conjunction of The 2006 IEEE/WIC/ACM International Conference on Web Intelligence December 18-22, 2006, Hong-Kong
 V. Daloukas, V. Dai, E. Alikanioti, S. Sirmakessis “The Design of Open Source Educational Games for Secondary Schools” in the Proceeding of the International Workshop on "Gaming Design and Experience: Design for Engaging Experience and Social Interaction" organised in the 1st International Conference on PErvasive Technologies Related to Assistive Environments (PETRAE) 15-19 July 2008, Athens.
 Konstantinos Markellos, Marios Katsis, Spiros Sirmakessis, “Improving Web Content Delivery in eGoverment Applications”, in the Proceedings of the International Workshop on Applications with Artificial Intelligence (AAI'07) organised by IEEE International Conference on Tools with Artificial Intelligence (ICTAI 2007) published in “Tools and Applications with Artificial Intelligence”, Springer Berlin / Heidelberg, Studies in Computational Intelligence, Volume 166/-1, Pages 181-197, 2009
 Evanthia Faliagka, Petros Karkoulias, Maria Rigou, Spiros Sirmakessis, Giannis Tzimas, Athanasios Tsakalidis, “Investigating the integration of hand-held haptic devices in daily work activities: The case of a Tennis Coaching Assistant on iPhone” in A. Marcus (Ed.) Design, User Experience, and Usability, Pt I, HCII 2011, LNCS 6769, Springer-Verlag Berlin Heidelberg 2011, pp. 555–563.