MaciejM.RatajMaciejM., Attitudes to Standard British English and Standard Polish: a Study in Normative Linguistics and Comparative Sociolinguistics, Frankfurt: Peter Lang, 2016, s. 11, ISBN 978-3-653-05404-0, OCLC953657257(ang.).
AnnaA.BerlińskaAnnaA., Teaching Mother Tongue Polish, [w:] WitoldW.Tulasiewicz, AnthonyA.Adams (red.), Teaching the Mother Tongue in a Multilingual Europe, London–New York: Continuum, 2005, s. 163–173, ISBN 978-0-8264-7027-0, OCLC232292774(ang.), patrz s. 167.