text and translation with commentary
James H. Lesher
most of this book is available electronically through Google Scholar. Colby also has the physical book at BX258.X33 F73 1992
Search for references to the Olympic games in the Greek historian Herodotus by typing the word "olympic" into the search box on this page. Click on the blue link "More(6)" to see all the results. Click on the blue link to book and chapter number, to see the whole passage in which the reference occurs.
And what does the historian Thucydides say about the Olympic games? Search a translation of the text for the word "olympic" here.
Or try typing in "Panathenaea"
Lucian, Anacharsis - Fowler & Fowler translation, p. 190-212
Francklin translation (1780)
On the Death of Peregrinus - Fowler & Fowler p.84-7
Pindar, Pythian Odes - from the Perseus Digital Library