What is the appropriate or best way of citing Geneva Conventions of 19949?

The appropriate way to cite the Geneva Conventions of 1949 would be as follows:

Geneva Conventions of 1949, [full citation of the specific convention being referenced], [date of adoption], [available at URL if accessed online].

For example:

Geneva Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field, adopted on 12 August 1949, available at https://www.icrc.org/en/doc/assets/files/other/geneva-convention-1.pdf

It is important to include the specific convention being referenced, the date of adoption, and a URL if the document is accessed online.