custody of children

Muhtaram Mufti Saheb db ,
Assalaamu alaikum
A couple are divorced.
Both are Hanafi.
They have two sons : –
1. Yusuf 8 _ yrs old
2. Ahmad 5 _ yrs old
Question :
Accordinding to Islamic Jurisprusprudence , who has the right of custody of the two children ?
I would highly appreciate if you could give us the Islamic ruling on this matter.
Jazakumullah.
Your brother in Islam,