"The Atlantic Month" cited some of Professor Lawrence Lessig's findings in an article about Google's efforts to put copyrighted works online:

"Out-of- copyright works represent just one-sixth of the total available, according to an analysis by Stanford University’s Lawrence Lessig."

"Once the opportunities of printed distribution are used up, the value of most books quickly dissipates, as they gather dust in libraries and used-book stores—they become part of the 75 percent of titles still copyrighted but out of print identified in Lessig’s study. Google Book Search could offer them a whole new life."