TY  - BOOK
AU  - Johnson,Ned K.
TI  - Biosystematics of sibling species of flycatchers in the Empidonax hammondii - oberholseri - wrightii complex
PY  - 1963///
CY  - Berkeley, Los Angeles
PB  - University of California Press
KW  - Empidonax
N1  - Bibliography: p. 216-220
ER  -