Attached Link: http://www.webster.com/cgi-bin/dictionary?va=Series

Just to let you know, 'series' is both singular and plural. There's no such word as 'serie'. Not trying to be mean, I've just been seeing people say 'serie' all over the web lately and it's makin' me twitch. And better to hear it from me than the guy who grades your term paper, right?