Mardofel, B. 2011. The letters sent by and to Chopin as a source of information for research on Tytus Woyciechowski family. Studia z Historii Społeczno-Gospodarczej XIX i XX Wieku. 9, (Jan. 2011), 251–285. DOI:https://doi.org/10.18778/2080-8313.09.15.