[Autore 1909]
[Bindel 2007b][Bindel & Henel 2007]
[Clark 2007a]
[Delbecque 2007]
[Gallois 1909][Girard 2011][Gruijs 1976]121-123
[Henel 2007][Hogg 2006b][Hogg 2007e]
[Martin 1975]
[Nabert 2007c]
NBC 2005b, beelden 246-249
[Pfaffl 2007]
[Timmermans 2007d]
