00401nas a2200157   4500000000100000008004100001100001800042700000500060700001800065700001700083700001900100700001600119245008900135300001200224490000700236       2009                            d1 aTaylor Colman1 a1 aFitzharris M.1 aMiddleton P.1 aStevenson Mark1 aJan Stephen00aA systematic review of the cost and benefit of helicopter emergency medical services  a10-20. 0 v41