Warren’s 1867 work is described in Charles Warren, Underground Jerusalem (London: Richard Bentley & Son, 1876), pp. 164–189. The results of the 1868 expedition were first published in 1869 in a little-circulated, untitled report to the members of the Palestine Exploration Fund (PEF). This report is in the library of the PEF in London, bound in a volume titled Palestine Exploration Fund Proceedings and Notes, 1865–1869. Warren’s findings are on pp. 14–16 of a longer account of a journey up the Jordan made in February–March 1868, which included soundings at Jericho and eight other tells in the vicinity. The report of the 1868 work was reprinted in Underground Jerusalem, pp. 192–197, and in The Survey of Western Palestine, Vol. III, by C. R. Conder and H.H. Kitchener (London: Committee of the PEF, 1883), pp. 224–226. Warren’s reports have been incorrectly cited by subsequent investigators: John Garstang (“Jericho: City and Necropolis,” p. 3, see endnote 8), Kathleen Kenyon (p. xxiii in Jericho 3, see endnote 18) and Piotr Bienkowski (p. 189 in Jericho in the Late Bronze Age [Warminster, UK: Aris & Phillips, 1986]).