Memmott, J, Baude, M, Kunin, W E, Boatman, N, Conyers, S, Davies, N E, Gillespie, M, Morton, R D & Smart, S M 2016, ' Historical nectar assessment reveals the fall and rise of floral resources in Britain ', Nature, vol. 530, no. 7588, pp. 85-88 . https://doi.org/10.1038/nature16532