Franceschini T., Lundqvist S.-O., Bontemps J.-D., Grahn T., Olsson L., Evans R., Leban J.-M. Empirical models for radial and tangential fibre width in tree rings of Norway spruce in north-western Europe. 2012. Holzforschung. 66. 2. 219-230. 10.1515/HF.2011.150.