Godamn do I love portaits, and god damn are these some great 2 coloured portraits.
Whoa, that was fast! 
Here are the correct guesses:
King, ?, Lovecraft, Dickens, ?
Martin, Pratchett, Poe, ?, ?
Tolkien, Asimov, Orwell, Shakespeare, Pessoa
5: Hunter S Thompson ?
7: is Terry Pratchett
9: Steinbeck, Maupassant?
These are great portraits, love the economy :)
building off of what solrac said:
stephen king, ? ,lovecraft, dickens, ?
grr martin, ? ,poe, ? , ?
tolkien, asimov , orwell, shakespeare, pessoa
these portraits are great, very effective use of two colors.
*2016
I actually love these though, even though I don't know most of them 
I might do something similar myself...
Nice portraits. I like the variety of facial details. Nice stuff.
8 out of 15.
I recognize H. P. Lovecraft, Charles Dickens, George R. R. Martin, E. A. Poe, Isaac Asimov, George Orwell, William Shakespeare, and Fernando Pessoa.
Brilliant work btw.
The only difference between the sane and the insane is that the sane have the power to lock up the insane.
The escritores appear on PixelJoint! I promise I won't spoil the fun this time ;)
Great portraits!