No... that would be EYZ, and I'm not easy.

Damn, I can't give you mojo for that...

As MBC pointed out, Stunk & White (as well as Modern Language Association, Economist, Purdue's Online Writing Lab) indicate that if the "es" is pronounced, it should be written 's. As for supporting sources, since most major sources actually support using 's as the standard case and using s' as the exception based on pronunciation, I'll site some that support said exception: The Guardian (admittedly a UK source), Emory, American Heritage/Bartlby.

Strunk & White is full of all sorts of crap so I've mostly stopped viewing them as a decent source, but like was said way up above, no matter what position you take on the rules of s-ending possessive nouns you'll probably be able to find some source that agrees with you.

So again, no matter how it is done someone important will think you're doing it wrong. So just pick a method that you're comfortable with and be consistent.

Personally I think the the possessive apostrophe is (and the contraction apostrophe) are unnecessary grammatically so let me be the first to advocate that you make a bold linguo-political statement and just not use them at all.

When I was editing (yes, believe it or not, I was an editor for several city-wide publicatons for many years) we developed our style guide and stuck with it. The use of the possessive apostrophe was our standard. But, as mentioned several times before, there are generally sources that will disagree with any particular style guide. I just went with consistency.

No...never mind...I'm not touching this either.

I can't be the only one who was surprised and frightened by this?

?

.

;

Punctuation