[otrs] change customer frontent customer company text

Hi all, I'm using a localized version of OTRS and the value for "Company Tickets" in the customer frontend in Turkish : "Müşteri Biletleri" I want to change the text of company tickets button to something else rather than "Müşteri biletleri" something like "Department" It's probably predefined in a configuration file.. I want to learn the name of the file so i can change it. Thanks & Regards, Sarper Saridal