Zorrilla-Vaca A, Mathur V, Wu CL, Grant MC (July 2018). "The Impact of Spinal Needle Selection on Postdural Puncture Headache: A Meta-Analysis and Metaregression of Randomized Studies". Regional Anesthesia and Pain Medicine. 43 (5): 502–508. doi:10.1097/AAP.0000000000000775. PMID29659437. S2CID4956569.
Zorrilla-Vaca A, Mathur V, Wu CL, Grant MC (July 2018). "The Impact of Spinal Needle Selection on Postdural Puncture Headache: A Meta-Analysis and Metaregression of Randomized Studies". Regional Anesthesia and Pain Medicine. 43 (5): 502–508. doi:10.1097/AAP.0000000000000775. PMID29659437. S2CID4956569.
Zorrilla-Vaca A, Mathur V, Wu CL, Grant MC (July 2018). "The Impact of Spinal Needle Selection on Postdural Puncture Headache: A Meta-Analysis and Metaregression of Randomized Studies". Regional Anesthesia and Pain Medicine. 43 (5): 502–508. doi:10.1097/AAP.0000000000000775. PMID29659437. S2CID4956569.