Technically, ATM, it's a perfectly valid way to pluralize acronyms/initialisms. It's simply a matter of style and personal preference.
http://english.stackexchange.com/questions/503/what-is-the-correct-way-to-pluralize-an-acronym
Technically, ATM, it's a perfectly valid way to pluralize acronyms/initialisms. It's simply a matter of style and personal preference.
http://english.stackexchange.com/questions/503/what-is-the-correct-way-to-pluralize-an-acronym