linux - How can I print two small files on the same page with a2ps?

I'm using Ubuntu Linux 12.0.4.1 LTS and I like the auto-formatting that a2ps does. I just want to print several small files using as few pages as possible.
Example: a2ps file1.c file2.c file3.c file4.c
These will print out (depending on printer settings) on their four separate pages, or on opposite sides of two two-sided pages, like this:

--- page 1---

side 1: file1.c text blank column

side 2: file2.c text blank column

--- page 2 ---

side 1: file3.c text blank column

side 2: file4.c text blank column

I want to have them all on one sheet of paper:

--- page 1 ---

side 1: file1.c text file2.c text

side 2: file3.c text file4.c text