Gillespie, D.; Berggren , P.; Brown , S.; Kuklik , I. .; Lacey , C.; Lewis , T.; Matthews , J.; McLanaghan , R.; Moscrop , A.; Tregenza , N. Relative Abundance of Harbour Porpoises (Phocoena Phocoena) from Acoustic and Visual Surveys of the Baltic Sea and Adjacent Waters During 2001 and 2002. JCRM 2023, 7, 51-57.