However, its reliability has been widely called into question and placed under careful examination by contemporary specialists in the field of the Old East Slavonic history. The first doubts about trustworthiness of the narratives were voiced by Nikolay Karamzin in his "History of the Russian State", which brought attention to Nestor's questionable chronology and style of prose. Building upon Karamzin's observations, further inquiries into the philology of the "Rus Primary Chronicle" shined more light on various weaknesses in the text's composition. According to Dmitry Likhachov, the chronicle exhibits the presence of plentiful "fillers" that were added "post factum" and, in effect, "destroyed the narrative's logical progression."