Dating the old testament
All these manuscripts are mere copies, and the great majority of them are copies of copies, yet ultimately they all derive from the originals.
Among the Amarna letters are appeals from a Canaanite king Abdi-Hepa of Jerusalem to Amenhotep IV (Akhenaten; prob. 19), which describe the city as in imminent danger of conquest by the Habiru.
560 BCE; but some scholars have termed his reasoning inadequate, and the history may have been further extended in the post-exilic period.
Scholars recognise three "sections" in the Book of Isaiah: Proto-Isaiah (the original 8th century Isaiah); Deutero-Isaiah (an anonymous prophet living in Babylon during the exile); and Trito-Isaiah (an anonymous author or authors in Jerusalem immediately after the exile).
This book is the best I've ever seen on this subject. As I read through the book I carefully underlined key observations, facts and conclusions, and entered notes of my own, interacting with almost every page.
The indexes and references are extensive and quite useful.