Ens et al. (1993), Klaassen & Ens (1993)†, Lourenço et al. (2018)†, Morrier & McNeil (1991)†, Stienen et al. (2008)†, Weis & Weis (2004)†, Zwarts & Blomert (1990), Zwarts & Dirksen (1990)†
Entries marked with † represent indirect references to location through citation.