madrobins | Query

I am getting alarmingly hung up on this question--a happy way of not allowing myself to write, I suppose. Does anyone know how or where to find information on forms of address in Medieval Italy--not so much the way the nobility was addressed, but how people in the middle class addressed each other, and how children would address adults? Most common titles now (Mr., monsieur, signor) are derived from my lord, and clearly a baker wouldn't call his neighbor the blacksmith my lord. Finding this bit of data is remarkably difficult--I did find a book I'd love to look at: Medieval Italy: An Encyclopedia. Only it's $350, and the SF Public Library doesn't seem to have a copy. So if anyone has any special knowledge, I'd love to hear it.