The Black Art of Estimation
http://www.onemanwrites.co.uk/2009/01/13/the-black-art-of-estimation/

McLean, Gordon
One Man Writes
2009

Abstract:

Estimating the amount of time it takes to write documentation is tricky as it relies on many differing, subtle, factors and, for many people working outside of a highly regimented and heavily project managed team, it tends to boil down to a mixture of guesswork and experience. However, it’s not impossible to come up with a more reasoned estimate as long as you don’t mind doing a little planning.