John Langdon Sibley, Clifford Kenyon Shipton, Sibley's Harvard Graduates, 1999, page 83. The relevant passage begins "After the service, the procession retraced its steps to the Granary Burying Ground, where the coffin was temporarily deposited."
Alfred S. Roe, The New England Magazine The Governors of Massachusetts: Part 1, Volume XXV No. 5, January 1902, page 540. The relevant section is "The Old Granary Burying Ground, so full of precious remains, also received his with all the honors that the Commonwealth could pay to his memory. His name ends the list of Governors connected with the Revolution, and also of those who were buried at the Old Granary. The body of Governor Eustis was afterwards removed to Lexington where it now lies."