Name Info Provider Link
free resource BioMed Central https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-018-3070-0
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/30572905/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/30572905
free resource Spiral, Imperial College Digital Repository http://hdl.handle.net/10044/1/66488