The NH2-terminal amino acid sequence of the immunochemically partial identical major allergens of Alder (Alnus glutinosa) Aln g I, birch (Betula verrucosa) Bet v I, hornbeam (Carpinus betulus) Car b I and oak (Quercus alba) Que a I pollens.Ipsen H, Hansen OC.Mol Immunol. 1991 Nov;28(11):1279-88. 

Immunochemical characterization of reference alder (Alnus glutinosa) and hazel (Corylus avellana) pollen extracts and the partial immunochemical identity between the major allergens of alder, birch and hazel pollens. Ipsen H, Bøwadt H, Janniche H, Nüchel Petersen B, Munch EP, Wihl JA, Løwenstein H.Allergy. 1985 Oct;40(7):510-8. 

Complementary DNA cloning and expression in Escherichia coli of Aln g I, the major allergen in pollen of alder (Alnus glutinosa).Breiteneder H, Ferreira F, Reikerstorfer A, Duchene M, Valenta R, Hoffmann-Sommergruber K, Ebner C, Breitenbach M, Kraft D, Scheiner O.J Allergy Clin Immunol. 1992 Dec;90(6 Pt 1):909-17.