{TAIL ~ Such filters} are constructed as {HEAD ~ planar filters}, for instance as described in French Patent No 2 422 268, U.S. Pat Nos. 4,791,391 or 4,070,084 
{ TAIL ~ Such filters } are constructed as { HEAD ~ planar filters } , for instance as described in French Patent No 2 422 268 , U.S. Pat Nos . 4,791,391 or 4,070,084
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH