Kirchoff, B.K., Pfeifer, E. and Rutishauser, R. 2008. Plant structure ontology: How should we label plant structures with doubtful or mixed identities?. Zootaxa. 1950, 1 (Dec. 2008), 103–122. DOI:https://doi.org/10.11646/zootaxa.1950.1.10.