Of these, the esters of acetic acid, {HEAD ~ especially acetic acid methyl esters} and {TAIL ~ ethyl esters}, are particularly preferred 
Of these , the esters of acetic acid , { HEAD ~ especially acetic acid methyl esters } and { TAIL ~ ethyl esters } , are particularly preferred
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH