The sulfur contents reach {HEAD ~ up to 15,000 ppm}, {TAIL ~ preferably between 4,000 and 9,000 ppm} 
The sulfur contents reach { HEAD ~ up to 15,000 ppm } , { TAIL ~ preferably between 4,000 and 9,000 ppm }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL