SEARCH Articles Figures Tables The seven basic designs and some variations of them are pictured and described in the reference cited above and by R. K. Johnson Combustion 50 [Publishers Imprint] [Publishers Imprint] See Also: The seven basic designs and some variations of them are pictured and described in the reference cited above and by R. K. Johnson Combustion 50 The seven basic designs and some variations of them are pictured and described in the reference cited above and by R. K. Johnson Combustion 50 The seven basic designs and some variations of them are pictured and described in the reference cited above and by R. K. Johnson Combustion 50 The seven basic designs and some variations of them are pictured and described in the reference cited above and by R. K. Johnson Combustion 50