The name Sugsin(肅愼) appears in historical records covering the 2nd and 3rd century AD. In the conventional view, it was interpreted that the Sugshin in the 'Pre-Qin(先秦) period' literature was projected into the 3rd-century Eublu(挹婁) for political purposes. However, this conventional view is a opportunist perception that lacks specific study of the times. Sugsin and Eublu, which appear in Samgugji(三國志), are geographically related to Ogjeo(沃沮). And Ogjeo is related to Bulnaeseong(不耐城), and Bulnaeseong is the same place as Gugnaeseong(國內城). Considering this location relation, it can be seen that the original Ogjeo was located in a different area from the Dongogjeo(東沃沮). It also reveals that Sugsin and Eublu were separate political organizations. In addition, the location of Danloseong(檀盧城) the base of Sugsin seen in Samgugsagi(三國史記), can be determined through Yosa(遼史), Geumsa(金史), and Cheongsago(淸史稿). This confirms that Sugsin in Samgugji was not an ancient illusion projected in Eublu.
Il Hwan Kim (Sun,) studied this question.