{HEAD ~ The impedance value} is added to a series connected resistor to provide {TAIL ~ the output impedance} 
{ HEAD ~ The impedance value } is added to a series connected resistor to provide { TAIL ~ the output impedance }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL