where did these popular aeroplanes - pratt & whitney r-1860 hornet b and allison model 250 originate ?
SELECT DISTINCT var_uri where brack_open dbr_Pratt_&_Whitney_R-1860_Hornet_B dbp_nationalOrigin var_uri sep_dot dbr_Allison_Model_250 dbp_nationalOrigin var_uri brack_close