1. Hjalmarsson G, Thoren J, Grape U, Malmquist G, Eriksson R, Kvarngren M. After-service analysis of the 32 year old HVDC cable Gotland 1. In: 1992 International council on large electric systems (CIGRE) sessions, Paris, France, Paper 21–302; Aug. 1992.
2. Subsea HVDC connections. Available: http://www.highvoltage.ecs.soton.ac.uk/research/project.php?id=932.
3. List of HVDC projects with marine infrastructure. Available: www.envirogulf.com/hvdc.html.
4. ABB website. The Gotland HVDC power links. Available: http://new.abb.com/systems/hvdc/references/the-gotland-hvdc-link.
5. High voltage direct current (HVDC) transmission systems technology review paper;Rudervall,2000