Vajrabhaya L, Korsuwannawong S, Karnasuta P, Kaewduang B, Ratanachai P, Aneakgerawat S, Kuntiyaratana S, Thanakittipoom W, Thongburan O.
A Novel 20° X-ray Angle Shifter for Superimposed Canal Separation. 
World J Dent
2021;
12
(2):126-130.