In this article by Choi G et al, the author would like to acknowledge that Fig. 5 was taken from the source : https://www.youtube.com/watch?v=1tJ-2WXFF6Q&feature=youtu.be and https://www.youtube.com/watch?v=S75qyUrI7Co&feature=youtu.be. These videos are of the patients operated by Dr. Hyeun Sung Kim, Neurosurgery Specialist / Vice President of Suwon Nanoori Hospital, South Korea. For publishing these pictures in the manuscript, necessary permission had been taken.
On the page 490, the legend of Fig. 5 should be corrected as follow.
Also, on page 497, References should be added as below.
23. Kim HS : Percutaneous Endoscopic Transforaminal Lumbar Discectomy (PETLD) by Dr. Hyeun Sung Kim-01. Available at : https://www.youtube.com/watch?v=1tJ-2WXFF6Q&feature=youtu.be
24. Kim HS : Percutaneous Endoscopic Interlaminar Lumbar Discectomy (PEILD) by Dr. Hyeun Sung Kim-01. Available at : https://www.youtube.com/watch?v=S75qyUrI7Co&feature=youtu.be