Scholars tended to locate them on a large territory, N. P. Barsov situated the Croats in the wide area of Carpathian Mountains, on the slopes of Tatra Mountains to the river Tisza and Prut on the South, to the Dniester to the East, and the Vistula to the North. Some scholars considered that White Croatia took in Nisa and Upper Elbe in the West, to Bug and Upper Prut and Siret in the East. According to Francis Dvornik, White Croatia extended from the Southern Bug and rivers Wieprz and San along the Poland-Ukraine border, to the slopes of Carpathian Mountains, including the Northern part of Slovakia, then from the rivers Netolica and Dudleba in upper Vltava, through Cidlina to the Krkonoše Mountains to the North and North-West. O. A Kupchynsʹkyĭ believed that Eastern Croats had territory from Prykarpattia (at the confluence of the rivers Laborec and Ondava at the crest of the Carpathian Mountains), valley of Beskids, western coast of the river Wisłoka, along Sandomierz valley until middle San, near Dunajec and left coast of Vistula. He said they also likely occupied the upper watershed of the Tisza river at the Ukraine-Slovakia border. In other words, much of the lands of present-day Czech Republic, Poland and Ukraine. Sedov sharply criticized such assumptions, saying "these hypothetical constructions are now of purely historiographic interest, since they do not find any confirmation in archaeological materials".