found: Dickson, P. Labels for locals, 2006(Turkmenistan: Turkmen, pluralized Turkmens. Turkmen comes from Persian, and is also an adjective. Turkoman (or Turcoman) denotes the same ethnic group, as a noun (pluralized Turkomans or Turcomans) or adjective. There is some evidence of Turkmenistani as a national adjective, but whether it will emerge as a useful demonym remains to be seen. Because Turkmens live in several different countries besides Turkmenistan, the ethnic significance of the word should be kept in mind.)
found: CIA The world factbook, via WWW, Apr. 1, 2012(Turkmenistan: Nationality: noun: Turkmen(s), adjective: Turkmen)
found: Dictionary.com, Apr. 1, 2012(Turkmen: the language of the Turkman people, a Turkic language spoken mostly east of the Caspian Sea in Turkmenistan but also in parts of European Russia, Iran, and the Caucasus. Also, Turkoman, Turcoman; Turkman: noun, plural -men. a native or inhabitant of Turkmenistan.)
found: National geographic style manual, via WWW, Apr. 1, 2012(Turkmenistan. Nationality (noun and adjective): Turkmen)