1. Inclusion Europe. 2009. Information for all. European standards for making information easy to read and understand. http://inclusion-europe.org/images/stories/documents/Project_Pathways1/Information_for_all.pdf Inclusion Europe. 2009. Information for all. European standards for making information easy to read and understand. http://inclusion-europe.org/images/stories/documents/Project_Pathways1/Information_for_all.pdf
2. Revision by Misako Nomura Gyda Skat Nielsen and Bror Tronbacke. Revision by Misako Nomura Gyda Skat Nielsen and Bror Tronbacke.
3. Plain Writing Association. http://www.plain-writing-association.org Plain Writing Association. http://www.plain-writing-association.org
4. Hannu Virtanen. 2009. Selkokielen käsikirja [The Handbook of Easy-to-read]. Helsinki Opike. Hannu Virtanen. 2009. Selkokielen käsikirja [The Handbook of Easy-to-read]. Helsinki Opike.