While purchasing the first ticket, you can mark the Return button, or after purchasing one-way, you can re-enter the system and purchase the return tickets by examining the reverse route sign with the reverse route sign.
When you search for flights between Hanoi and İstanbul, all active companies and flight times on the date you entered are listed. You can find the cheapest flight tickets by sorting this list by price.
The most frequently used airline companies from Hanoi to İstanbul are generally
Türk Hava Yolları,
Emirates,
Asiana Airlines,
Thai Airways Intl,
Sichuan Airlines,
Korean Air,
Oman Air,
Vietnam Airlines,
Qatar Airways,
Singapore Airlines,
China Eastern Airlines
are companies.