{HEAD ~ The following esters} can also be used to advantage: formic acid methyl esters, ethyl esters and propyl esters, acetic acid methyl esters, ethyl esters and propyl esters, propionic acid methyl esters and ethyl esters and {TAIL ~ butyric acid methyl esters} 
used to
{ HEAD ~ The following esters } can also be used to advantage : formic acid methyl esters , ethyl esters and propyl esters , acetic acid methyl esters , ethyl esters and propyl esters , propionic acid methyl esters and ethyl esters and { TAIL ~ butyric acid methyl esters }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL