Before revision:  Two sources of BitTorrent data were utilized: meta-data files that describe the content of resources shared by BitTorrent users and logs of the currently one of the  most popular BitTorrent clients -  . is based on {  rather newly released UDP-based    protocol that is claimed to be more efficient than TCP-based clients.
After revision:  Two sources of BitTorrent data were utilized: meta-data files that describe the content of resources shared by BitTorrent users and logs of the currently one of the most popular BitTorrent clients -  . \mu { rather newly released UDP-based  protocol that is claimed to be more efficient than TCP-based clients.