lha sar yong ba'i 'jar man pa thog ma en si the tre hpher dang khong gi thsan rig rtog zhig tshogs pa/, kra'o kung ru'e/; see BDRC (W3CN25663), vol. 2, pp. 615-629
"Schäfer collection":http://www.loc.gov/pictures/item/2010651980/ at the Library of Congress with ca. 35,000 items (accessed: 2016-06-16)
Ernst Schäfer files (Notes or journal of a Deutsche Tibet Expedition, 1938-1939) at the Library of Congress, box 828, reel 491-492; cf. "German Captured Documents Collection:A Finding Aid to the Collection in the Library of Congress Manuscript Division, Library of Congress, [revised 2012 October]":hdl.loc.gov/loc.mss/eadmss.ms011148.3, p. 108 (accessed: 2016-06-16). Schäfer's unpublished and hand-written notes kept in the manuscript division at the Library of Congress are also referred to by Isrun Engelhardt , Mishandled Mail: The Strange Case of the Reting Regent’s Letters to Hitler (Online version on "Tibetan Buddhism in the West":http://info-buddhism.com/index.html), note 5 (accessed: 2016-06-16)