We know that it's often difficult to find something regarding the history of the double bass and also violone. They are different instruments, but their history is quite common.
Well, if from a point of view regarding to "written books" we would find something, but at the end only "The new history of the double bass " by Paul Brun remains the only point of referrement for everyone. But there also a question of translation.
So I decided to find something on the Net, and surely the chances of finding something interesting were higher.
Give a look at WWW.EARLYBASS.COM by Jerry Fuller and you will enter in another world in which there are a lot of studies about violone and double bass and much more.
In this site there's a very beautiful link to conect to other sites regarding less or more to double bass.