LTReikšminiai žodžiai: Senieji raštai; Konstantinas Sirvydas; Jonas Jaknavičius; Leksikografiniai šaltiniai; Old writings; Konstantinas Sirvydas; Jonas Jaknavičius; Lexikographic sources.
ENThe paper offers an overview of research done in the second half of the 20th and the beginning of the 21st century and focusing on some selected works of Konstantinas Sirvydas. The author of the present paper introduces the results of his previous dialectological and textological research into the works by Konstantinas Sirvydas and Jonas Jaknavičius. Linguistic and spelling elements found in the language of an anonymous assistant of K. Sirvydas and J. Jaknavičius are described. The dialectological analysis gives a clue to K. Sirvydas’ native dialect and its location - east of Anykščiai. J. Jaknavičius’ native dialect is located in the eastern part of the 17th century Lida region; the dialect of the anonymous assistant is located to the west or north-west from the birth place of J. Jaknavičius. [From the publication]