Head to Blue Basilica, then to the stronghold of Surite. From there head down and to the right, across the river.
Found in Argent, to the right of the stronghold of Carella.
You can buy this book in the store in Alba. Specifically the stronghold of Vertze. It costs quite a lot of money, however.
Another one can be found in Barpheth, just head to Sondrio. From there head down and to the right and wonder around until you find it.
Head to Dardunnelles, and go to the town of Melphy. The time needs to be between 18:00 and 21:00 on either the 6th, 15th, or 21st of the month.
Found in Ptia, below and to the right of the town of Furge.