When naming a group like, "The Writers Group" do you use an apostrophe?

I have found three different usages defined, "The Writer's Group", "The Writer's Group", and "The Writers' Group". What is correct?





Note, the book, "The Writer's Market" is written just like this, and "Reader's Digest" is also titled in this way. Anyone have the definitive answer backed up with a authorative reference?

When naming a group like, "The Writers Group" do you use an apostrophe?
My dear Ms. Truss would have a field day with this. If it was Writer's Group, it would mean that one writer had a group. If it was Reader's Digest it would be a lot of work to publish a magazine for one reader. It would be Writers' Market and Readers' Digest and Writers' Group - denoting that there is more than one reader or writer. Pax-C
Reply:you miss the point. writer's group could mean 'a group for the average/common writer'. Like reader's digest. it doesn't necessarily mean it is a group belonging to many writers.
Reply:yes you do because its a group that belongs to writers so it is Writers' i sincerley doubt that there is just one writer to whom it belongs.
Reply:Actually, it's a group belonging to more than one writer, so you put the apostrope after the "s"...the writers' group. No authoritative reference, nothing to back this up...just grammatically correct to take a possessive plural and put the apostrophe after the plural.