RT Journal Article SR Electronic T1 Simple working sheath for lumbar and lumbosacral spine: technical note JF BMJ Innovations JO BMJ Innov FD All India Institute of Medical Sciences SP 478 OP 481 DO 10.1136/bmjinnov-2020-000558 VO 7 IS 2 A1 Deepak Kumar Jha A1 Jaskaran Singh Gosal A1 Jigish Ruparelia A1 Nitin Kumar A1 Tarunesh Sharma A1 Pradeep Kumar Bhatia A1 Pushpinder Khera YR 2021 UL http://innovations.bmj.com/content/7/2/478.abstract AB