1. Castelijns, H., W. van Kerkhoven, and J. Maebe. 1997. Birds of the Sieperda marsh. A report published by conservation society "Steltkluut, Terneuzen."[in Dutch]
2. Castelijns, H., W. van Kerkhoven, A. Wieland, and J. Maebe. 2000. Ten years Sieperda marsh. An evaluation of developments in bird populations. A report published by conservation society "Steltkluut, Terneuzen."[in Dutch]