Prototractatus an early version of Tractatus logico-philosophicus - Wittgenstein, Ludwig; McGuinness, B. F. [ed.]; Nyberg, T. [ed.]; Von Wright, G. H. [ed.]; Pears, D. F. [tr.]; McGuinness, B. F. [tr.] (London Routledge and K. Paul, 1971)
Text in English and German
Keywords: Logic, Symbolic and mathematical; Language and languages -- Philosophy