Here is a link to Dena Epstein's book. Only parts of it are on line, but if you scroll down to Chapter 9, you will find that it is on "Worksongs" and has many of the quotes and references that we have been working with so far.

http://books.google.com/books?id=WUHaLYzhiSoC&pg=PA68&dq=Worksongs&cd=5#v=onepage&q=Worksongs&f=false