I'm reading an historical overview of economic thought. The book talks about the Erlenmeyer Tablets as recording product valued/measured in 'Female Labor Days' in ancient Sumeria. I was curious what exactly this metric means or is describing?

As an unrelated question, the book mentions M. I. Finley's book 'The Ancient Economy' and, since the book was published in 1970, I'm curious if there are any better books on ancient economics/economies. I've heard the book is criticized for using literary sources, though I don't know whether or not that's accepted practice by historians.

Thanks!