1. Anderson, A. W. (no date). A planned auxiliary language. No place of publication given, apparently self-published.
2. ApGawain, N., Hugon, P. D., Moore, J. L., & de Beaufront, L. (2008). Ido for all (edition 1.6).
http://idomondo.org/skolo.1.6.pdf
. Accessed 27 Apr 2010.
3. Bollack, L. (1900). Abridged grammar of the Blue Language (English version by Professor Tischer). Paris: Editions of the Blue Language.
4. Bothi, P. (2006) The
new personal international language Esata (draft edition 0.3).
http://www.beginnersgame.com/page_25.pdf
. Accessed 9 May 2010 (In this work the author’s name is given simply as PAFU, but an internet search indicated that his name is apparently Pafu Bothi).
5. Brown, P., & Levinson, S. C. (1987). Politeness. Cambridge: Cambridge University Press.