Contamination - highly-rated 4 volume zombie series for for free in Kindle edition
by Mark Frauenfelder from on (#17J5K)
I haven't read T.W. Piperbrook's Contamination post-apocalyptic zombie series but it has 4.1/5 stars with 744 customer reviews on Amazon. Right now you can get the first 4 books as the Kindle editions for free.