Also, it should be mentioned at this point that the description that follows {TAIL ~ concentrates} on Molecular Beam Epitaxy apparatus and methods of {HEAD ~ operation} 
Also , it should be mentioned at this point that the description that follows { TAIL ~ concentrates } on Molecular Beam Epitaxy apparatus and methods of { HEAD ~ operation }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD