From the web :
A simple rule to help you remember the difference between another and other is:
another + singular noun
other + plural noun
others (a pronoun to replace other + plural noun)
•I need another cup. (cup is singular so we use another)
•I need other cups. (cup is plural so we use other)
•I need others. (refers to other cups)
http://www.grammar.cl/english/another-other-others.htm