1. Aikhenvald, A. 2005. Evidentiality. Oxford: Oxford University Press.
2. Alonso-Ovalle, L., and P. Menéndez-Benito. 2003. Some epistemic indefinites. North-Eastern Linguistic Society 33: 1–12.
3. Baker, C.L. 1970. Double negatives. Linguistic Inquiry 1: 169–186.
4. Bornkessel-Schlesewsky, I., and M. Schlesewsky. 2009. Processing syntax and morphology. Oxford: Oxford University Press.
5. Buridant, C. 2000. Grammaire Nouvelle de l’Ancien Français. Paris: Sedes.