Carry-on Baggage Size and Rules, International flights
Carry-on bag allowance
TSA Carry-On Rules: Items You Can and Can't Take on a Flight in
Free Baggage Allowance
Airline Carry On Sizes, Carry On Luggage Size Guide
Carry-on Luggage Sizes and Weight Limits by Airline
Your Personal Item Size Cheat Sheet - Tortuga
United Airlines' carry-on luggage guide
United Airlines Carry-On Size & Luggage Policies
United Airlines Carry-On Size & Luggage Policies
The Carry-On Luggage Size Limitations on United Airlines
Baggage Policies of Regular and Low Cost Airlines - Traveler's Edition