Sources:
https://wiggersfurniture.blogspot.com/2011/01/story-of-kiid-kiyaas-golden-spruce.html
https://www.oregon.gov/ODF/Documents/ForestBenefits/SitkaSpruce.pdf
FROST HARDINESS AND DORMANCY IN CONIFERS by 1/ C. Glerum 1/
https://beerconnoisseur.com/articles/history-spruce-beer
https://www.conifers.org/pi/Picea.php
https://forest.jrc.ec.europa.eu/media/atlas/Picea_abies.pdf
https://bugwoodcloud.org/resource/files/25386.pdf
https://bonsai4me.com/speciesguides/picea-spruce-bonsai/
https://www.conifers.org/pi/Picea_jezoensis.php
https://soundcloud.com/masahiro-bessho/sets/tonkori-sound-sketch
https://www.visittrentino.info/en/articles/snow-and-nature/violin-s-forest