459117 Geere, R. (1986). Forth: The next step. Wokingham, Eng. : Addison-Wesley.
Lua i Stíl Chicago (17ú heag.)459117 Geere, Ron. Forth: The Next Step. Wokingham, Eng. : Addison-Wesley, 1986.
Lua MLA (9ú heag.)459117 Geere, Ron. Forth: The Next Step. Wokingham, Eng. : Addison-Wesley, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.