Livezey, KB (2009). "Range expansion of Barred Owls, part I: chronology and distribution". American Midland Naturalist. 161: 49–56. doi:10.1674/0003-0031-161.1.49.
Livezey, KB (2009b). "Range expansion of Barred Owls, part 2: facilitating ecological changes". American Midland Naturalist. 161 (2): 323–349. doi:10.1674/0003-0031-161.2.323.
Livezey KB (2010). "Killing Barred Owls to Help Spotted Owls II: Implications for Many Other Range-Expanding Species". Northwestern Naturalist. 91 (3): 251–270. doi:10.1898/NWN09-38.1. JSTOR40983223.
Livezey KB (2010). "Killing Barred Owls to Help Spotted Owls II: Implications for Many Other Range-Expanding Species". Northwestern Naturalist. 91 (3): 251–270. doi:10.1898/NWN09-38.1. JSTOR40983223.
Carpenter, Anita (February 2003). "What Color is a Bluejay?". Wisconsin Natural Resources Magazine. Diarsipkan dari versi asli tanggal 2018-07-31. Diakses tanggal 2012-10-21.Parameter |url-status= yang tidak diketahui akan diabaikan (bantuan)
wi.gov
dnr.wi.gov
Carpenter, Anita (February 2003). "What Color is a Bluejay?". Wisconsin Natural Resources Magazine. Diarsipkan dari versi asli tanggal 2018-07-31. Diakses tanggal 2012-10-21.Parameter |url-status= yang tidak diketahui akan diabaikan (bantuan)