Name	Info	Provider	Link
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22977700/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/22977700
	free resource	M2PI	https://asianspinejournal.org/journal/view.php?doi=10.4184/asj.2012.6.3.199