multiple DS18B20 resolution set_up

Good day ,
I am using three DS18b20 temperature sensors. ( three wires system bus :+5vdc, GND , data )
I would like to have them set for 9 bit resolution to save time .
How could I do that ?
Any code available for setting up resolution in multiple sensor enviroment ?
Thanks for helping
Regards,
Ambrogio

I solved my problem.
The reading format is always the same disregarding resolution setiing.
Ambrogio