00521nas a2200193   4500000000100000008004100001100001500042700001400057700001500071700001200086700001800098700001500116700001600131700001600147245012800163250001600291300001200307490000800319       2013                            d1 aJenkins C.1 aPostma D.1 aAnzueto A.1 aMake B.1 aSimilowski T.1 aOstlund O.1 aEriksson G.1 aCalverley P00aFactor analysis in predominantly severe COPD: Identification of disease heterogeneity by easily measurable characteristics.  a15 Aug 2013  a1939-470 v107