no computers - A simple nonogram

Solve the nonogram.

                  _{(Click for a larger version.)}

Answer

Final answer is

or perhaps I should say

PSE.

I confess that I only bothered going this far by strict logical inference

before allowing myself to make the obvious assumptions about the structure of the solution, leading to this (where white and yellow should now be treated as equivalent):

whereupon it's clear how to get to the solution at the top.