Funded by the National Science Foundation PEET program (Partnerships for Enhancing Expertise in Taxonomy)
Siida, I. 1999. Harilik haavaĆ¼rask (Trypophloeusasperatus (Gyll) Eestis [Trypophloeus asperatus (Gyll) in Estonia]. Metsanduslikud Uurimused 31:181-183.