U. S. Service Dogs Registry

https://www.united.com/web/en-US/content/travel/specialneeds/disabilities/assistance_animals.aspx

https://customersupport.spirit.com/hc/en-us/articles/202096816-Can-I-bring-my-service-emotional-support-or-psychiatric-service-animal-on-my-flight-

https://www.southwest.com/html/customer-service/traveling-with-animals/index-pol.html

http://help.jetblue.com/SRVS/CGI-BIN/webcgi.exe?New,Kb=askBlue,Case=obj(3324)

https://www.hawaiianairlines.com/our-services/special-assistance/traveling-with-animals

http://faq.flyfrontier.com/help/may-i-bring-a-service-animal-or-an-emotional-support-animal-with-me-on-the-plane

https://www.delta.com/us/en/accessible-travel-services/service-animals

https://www.aa.com/i18n/travel-info/special-assistance/service-animals.jsp

https://www.allegiantair.com/contract-carriage

https://www.alaskaair.com/content/travel-info/accessible-services/specialservices-support-animals