^Stevens, Peter F. (2006). "The angiosperm phylogeny Website - a tool for reference and teaching in a time of change". Proceedings of the American Society for Information Science and Technology. 42. doi:10.1002/meet.14504201249.
Note: This is a selected list of the more influential systems. There are many other systems, for instance a review of earlier systems, published by Lindley in his 1853 edition, and Dahlgren (1982). Examples include the works of Scopoli, Batsch and Grisebach.