TY  - RPRT
TI  - Geographic variation in the song of Willow Flycatchers: Differentiation between Empidonax traillii adastus and E. t. extimus
AU  - J.A. Sedgwick
PY  - 2001
DO  - 10.1642/0004-8038(2001)118[0366:gvitso]2.0.co;2
UR  - https://pubs.usgs.gov/publication/1015200
ID  - 1015200
ER  -