Austria_ ÖGOR (Österreichische Gesellschaft für OR)
Belgium_

ORBEL (Belgian Operations Research Society)
Croatia_      CRORS HDOI
Czech Republic_ CSOR (Czech Soziety for Operations Research)
Denmark_ DORS (Dansk Selskab for Operationsanalyse)
Finland_ FORS (Finnish Operations Research Society)
France_ ROADEF (l'Association Française de Recherche Opérationnelle et d'Aide à la Décision)
Germany_ GOR (Gesellschaft für Operations Research)
Greece_ HELORS (Hellenic Operational Research Society)
Hungary_ HORS (Hungarian Operations Research Society)
Iceland_ ICORS (Icelandic Operations Research Society)
Israel_ ORSIS (Operations Research Society Israel)
Italy_ AIRO (Associazione Italiana di Ricerca Operativa)
Netherlands_ NSOR (Netherlands Society of Operations Research)
Norway_ NORS
Portugal_ APDIO (Associação Portuguesa de Instigação Operacional)
Slovakia_ SSOV (Slovenska Spolocnost pre Operacny Vyskum)
Spain_ SEIO (Sociedad de Estadistica e Investigación Operativa)
Sweden_ SOAF (Swedish Operations Research Society)
Switzerland_ SVOR (Schweizerische Vereinigung für Operations Research)
United Kingdom_ OR Society & OR Newsletters