From 9 February 2010 the famous Book of Henryków can be read fully digitalised at FIDES Digital Library. It is written in 1268-1273. Currently the book is held in the Diocesan Museum in Wrocław.
The Book of Henryków (Polish: Księga henrykowska, Latin: Liber fundationis claustri Sancte Marie Virginis in Heinrichau) is a Latin chronicle of the Cistercian abbey in Henryków (German: Heinrichau) in Lower Silesia. It is notable as the earliest document to include a sentence written entirely in what can be interpreted as an early Polish: „day ut ia pobrusa, a ti poziwai”. It is placed on the 24th page, 9th line from the bottom.
See also Book of Henryków in Wikipedia.