Change in spring arrival of migratory birds under an era of climate change, Swedish data from the last 140 years. - Kullberg, Cecilia; Fransson, Thord; Hedlund, Johanna; Jonzén, Niclas; Langvall, Ola; Nilsson, Johan; Bolmgren, Kjell (AMBIO - A Journal of the Human Environment, 2015)