Use of apostrophe s for possession

[sane]

Since we say:

This book is his.

which one (or are both) of these following sentences correct:

This is a book of Smith.
This is a book of Smith's.

[susiedqq]

You will hear: This is Smith's book.

You will probably never hear: This is a book of Smith's
(but it is gramatically correct)

[Jean-Frédéric]

Can you say: "This book is Smith's"?

[Anglika]

Yes.

Whose book is this?
This book is Smith's

You can also say:

This book of Smith's is an amazing exposition of current political errors.

[susiedqq]

Now, here's another thought: when the name already ends in an "s" - like the lat name, Williams - you can say:

1) This book of Williams' is really exciting.

or

2) This book of Williams's is really exciting.

But most people don't want to say the extra syllable and hear the sound of
"williams-ezz", so 1) is preferred.