Butler, Peter An analysis of the effect of COVID-19 on the crew change operation in the years 2020-2021 / Peter Butler. - viii, 38 pages : color illustrations ; 30 cm - B.Sc. (Hons) Nautical Science . Includes bibliographical references. Subjects--Topical Terms: Shipping--Personnel managementCOVID-19 Pandemic, 2020---Social aspects Dewey Class. No.: B.Sc. Nautical Science