Não informado. (1987). Miscellaneous Publications of the University of Utrecht Herbarium. University of Utrecht, Institute of Systematic Botany.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Miscellaneous Publications of the University of Utrecht Herbarium. Utrecht, Holanda: University of Utrecht, Institute of Systematic Botany, 1987.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Miscellaneous Publications of the University of Utrecht Herbarium. University of Utrecht, Institute of Systematic Botany, 1987.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.