Ellegren, H. and Wallin, K. 1991. Autumn migrating Bluethroats Luscinia s. svecica orient in an eastsoutheasterly direction at Gävle, East Sweden. Ornis Svecica. 1, 1 (Jan. 1991), 47–50. DOI:https://doi.org/10.34080/os.v1.23095.