All protocols accept, but do not require, evidence based on randomized controlled trials, and most others accept clinical controlled trials as appropriate sources of evidence. (psychology.wikia.com)
Once you make the choice to get help from appropriate sources, get lots of it. (mindbodygreen.com)
Historic operating and financial data, while providing useful insight into the economics of an airline operation, may not necessarily be the most appropriate source to project expected revenue. (newlawjournal.co.uk)