Åhas, R. (1999). Spatial and temporal variability of phenological phases in Estonia. Tartu University Press.
Chicago-viite (17. p.)Åhas, Rein. Spatial and Temporal Variability of Phenological Phases in Estonia. Tartu: Tartu University Press, 1999.
MLA-viite (8. p.)Åhas, Rein. Spatial and Temporal Variability of Phenological Phases in Estonia. Tartu University Press, 1999.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.