VTS

Norcontrol IT - A leading technology solutions provider of Vessel Traffic Management and Information Systems (VTMIS, VTS, AIS).
www.norcontrolit.com/

SOFRELOG - Supplying traffic control monitoring systems in maritime and air applications for civilian or military customers.
www.sofrelog.com

USCG Office of Vessel Traffic Management - Managing the U.S. system of Vessel Traffic Services (VTS)
www.uscg.mil/vtm/

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.
www.worldvtsguide.org/