1. John of Holland, Four Tracts on Logic (Suppositiones, Fallacie, Obligationes, Insolubilia)
2. Bradwardine, T. 2010. Insolubilia, Edited with English translation by Stephen Read. Leuven: Peeters.
3. De Rijk, L. M. 1982. ‘Semantics in Richard Billingham and Johannes Venator’, in A. Maierù (ed.), Engish Logic in Italy in the 14th and 15th Centuries, Naples: Bibliopolis, pp. 167–83.