Gul, O. 'Handbook of Public Relations' (Halkla İlişkiler El Kitabı),  TÜHİD, Türkiye Halkla İlişkiler Derneği Yayınları,  Taş Mektep Yayın Atolyesi, 2014.

Gul, O., 'Corporate Communication Management' (Kurumsal İletişim Yönetimi), Book Chapter, Editor: Assoc. Prof. Dr. Seda M. Cakar, Atatürk University Open Education Faculty Publishing, 2012

“Corporate Advertising” (Kurumsal Reklamcılık) Gul, O. Brandology (Markaloji), Book Chapter, Editor: Assoc. Prof. Dr. Filiz O. Demir, Giza Publishing, October 2012, İstanbul, “Sponsorship and Social Responsibility” (Sponsorluk ve Sosyal Sorumluluk).

Gul,O.  'İdeological Arena Media' , Book Chapter, Editor: Burcu Kaya Erdem, 'First Step to World of Media: Communication Faculties' (Medya Dünyasına İlk Adım: İletişim Fakülteleri)Beta Publishing, October 2012, İstanbul.

Gul, O. Human Rights – A Practice of Life (İnsan Hakları – Bir Gündelik Hayat Pratigi) - , Book Chapter, Editors: Edibe Sozen, Adem Ayten, Murat Iri, Alfa Publishing, March 2006, Published in Istanbul, “Disclosure of Human Rights of IHD and Mazlum-Der” (İHD ve Mazlum-Der’in İnsan Hakları Söylemi), collective study.

Gul, O. Through Advertisements (Reklamlarin Icinden), Book Chapter, Editors Mete Camdereli, Ahsen Deniz Morva, Nilnur Tandacgunes, Tablet Publishing, 2005, Published in Konya, “Turkcell’s Country Films in the Perspective of Oppositions” (Karşıtlıklar Perspektifinde Turkcell Memleket Filmleri).

Gul, O. 'Corporate Responsibility Awareness and AHI Organization' (Kurumsal Sorumluluk Farkındalığı ve Ahilik Kurumu), Proceeding, III. International Conference on Awareness,  5-7 December 2019, Çanakkale, Turkiye.

Gul, O. PERL (Partnership for Education and Research about Responsible Living) Conference 2011, Enabling Responsible Living. Maltepe University , 14-15 March 2011,  “The Role of Governments For Enabling Responsible Living: The Example of Turkish Automotive Industry”.

Gul, O. II. National Public Relations Symposium, New Orientations, Problems and Solutions in Public Relations in 21st Century, Kocaeli University Communication Faculty, 27-28 April 2006, “Reflection of PR Practice on Mass Media: The IKEA Sample”

Gul, O. 2nd International Symposium Communication in the Millennium, A Dialogue Between Turkish and American Scholars, Collaboration of Texas University, Anadolu University and Istanbul University, 17-19 March 2004, “Examining the Role of Agenda Setting in Public Relations Progress as an Issue: A Case Study”