Lim H., Oren R., Palmroth S., Tor-ngern P., Mörling T., Näsholm T., Lundmark T., Helmisaari H.-S., Leppälammi-Kujansuu J., Linder S. Inter-annual variability of precipitation constrains the production response of boreal Pinus sylvestris to nitrogen fertilization. 2015. Forest Ecology and Management. 348. 31-45. 10.1016/j.foreco.2015.03.029.