Hogstad O, Thingstad PG, Marc D. Gloger’s ecogeographical rule and colour variation among Willow Tits Parus montanus. Ornis Norv. [Internet]. 2009 Jan. 1 [cited 2024 Apr. 25];32:49-55. Available from: https://boap.uib.no/index.php/ornis/article/view/156