The file extension CTV3 - Citavi 3 Project File is actually a project style file that is created by the program called Citavi. This application is actually a management program for references and is used by the Microsoft Windows operating system. This file type often contains citation information from various sources. You must have the proprietary program mentioned earlier to view these files. The CTV3 - Citavi 3 Project File is actually known as an extremely durable and secure file type.