Holbrook، Martin (1999). "Real Time System to Aid Vessel Manoeuvering in the Derwent River". Coasts & Ports 1999: Challenges and Directions for the New Century; Proceedings of the 14Th Australasian Coastal and Ocean Engineering Conference and the 7Th Australasian Port and Harbour Conference. Engineers Australia: 279. مؤرشف من الأصل في 2020-06-03. اطلع عليه بتاريخ 2019-01-05.
Holbrook، Martin (1999). "Real Time System to Aid Vessel Manoeuvering in the Derwent River". Coasts & Ports 1999: Challenges and Directions for the New Century; Proceedings of the 14Th Australasian Coastal and Ocean Engineering Conference and the 7Th Australasian Port and Harbour Conference. Engineers Australia: 279. مؤرشف من الأصل في 2020-06-03. اطلع عليه بتاريخ 2019-01-05.