Optionally, only a portion of {TAIL ~ the sought digital content} is downloaded using single source download, establishing that such a portion of {HEAD ~ the sought content} is made available by the distributor 
Optionally , only a portion of { TAIL ~ the sought digital content } is downloaded using single source download , establishing that such a portion of { HEAD ~ the sought content } is made available by the distributor
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH