- Yasukawa, K., and W. A. Searcy. 1995. Red-winged Blackbird (Agelaius phoeniceus). The Birds of North America. Edited by P, G. Rodewald. Retrieved from: https://birdsna.org/Species-Account/bna/species/rewbla DOI: 10.2173/bna.184.
- Yosef, R. 1996. Loggerhead Shrike (Lanius ludovicianus). Birds of North America. Edited by P. G. Rodewald. Retrieved from: https://birdsna.org/Species-Account/bna/species/logshr DOI: 10.2173/bna.231.
- Young, M. A. 2012. North American Red Crossbill Types: Status and Flight Call Identification. Retrieved from: http://www.ebird.org/content/ebird/news/recrtype.