Final answer:
The Shasu appear in Egyptian literature in the Amarna Letters, which are a collection of correspondence from the New Kingdom period.
Step-by-step explanation:
The Shasu, who are Semitic-speaking cattle nomads, appear in Egyptian literature specifically in the Amarna Letters. These letters are a collection of correspondence, made up of cuneiform tablets, between the Egyptian administration and their representatives in Canaan and Amurru during the New Kingdom. The letters provide insight into the political relations and circumstances of that time, including the interactions with various peoples like the Shasu.