Hahahaha good luck with that :P
I would search PubMed and look at large health panel websites like WHO and governmental health agencies from different countries. I might check out Wikipedia too just for more ideas on sources/citations though obviously Wikipedia is not a citable reference.
I would NOT ask DS for "unbiased information" on this topic...
Mommy to my girl M (b. June 2011) and baby boy G (b. July 2013)