This small e-book in German available in the iBookstore is telling our own experience:

We had published the print edition of Tropenfrucht, what cost a pretty penny and forced us going through a lean spell.

It was in autumn, our garden was rich in vegetables and in the nearby forest strawberries, raspberries and mushrooms were in abundance. Instead of borrowing money from 'good fellas' we decided to do a little belt tightening.

Intentionally, we recorded in detail our menues and expenses: One hundred Swiss Francs were sufficient for one person to get a good nutrition during one month, providing that one has a little garden and knows the nature.

Learn more about the book by clicking on the cover.