SOFRELOG - Supplying traffic control monitoring systems in maritime and air applications for civilian or military customers. - http://www.sofrelog.com
World Vessel Traffic Services Guide - Designed to give Masters of ships, navigators, and interested persons, clear and concise diagrammatic and written information regarding the navigational requirements of the VTS Centres of the world. - http://www.worldvtsguide.org/
Norcontrol IT - A leading technology solutions provider of Vessel Traffic Management and Information Systems (VTMIS, VTS, AIS). - http://www.norcontrolit.com/