https://www.zupyak.com/p/4807886/t/pet-policy-how-much-does-delta-charge-for-a-pet-on-the-plane
https://www.zupyak.com/p/4807895/t/pet-on-board-charges-explained-for-united
https://www.zupyak.com/p/4807902/t/pet-policy-updated-american-charges-for-flying-with-pets