Gillespie, D., Berggren , P., Brown , S., Kuklik , I. , Lacey , C., Lewis , T., Matthews , J., McLanaghan , R., Moscrop , A. and Tregenza , N. 2023. Relative abundance of harbour porpoises (Phocoena phocoena) from acoustic and visual surveys of the Baltic Sea and adjacent waters during 2001 and 2002. J. Cetacean Res. Manage. 7, 1 (Mar. 2023), 51–57. DOI:https://doi.org/10.47536/jcrm.v7i1.757.