Pavol Żigo’s work, which opens the development of morphological maps in the OLA team, is worthy of the highest praise. It offers an interpretation of selected maps concerning declination of nouns, accompanied by detailed theoretical considerations of the process of changes in the declination system in Slavic languages. Drawing on extensive dialectal records, the Atlas offers an excellent overview of the complex development of declination of nouns in Slavic languages. This publication may serve as a model for further studies in this field.