RT Journal Article SR Electronic T1 The importance of precise, validated bony landmarks for blocks and radiofrequency ablation JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP rapm-2019-100879 DO 10.1136/rapm-2019-100879 A1 Shannon L Roberts YR 2019 UL http://rapm.bmj.com/content/early/2019/08/24/rapm-2019-100879.abstract AB