Currently when a drone is captured it is difficult to trace back to an owner.
But it is difficult to trace authorship for the W.P.A. guides.
The Hanks genealogy is difficult to trace, but Nancy appears to have been of illegitimate birth.
It is difficult to trace an attack to a specific individual in cyberspace.
Because of disconnection information between the two processing, it is difficult to trace continuously.
But it is difficult to trace how a rhythm migrated from one place to another, he said.
But criminal money is difficult to trace, it is silent and this is why it can be very dangerous".
Firm provenance is difficult to trace, especially for Tibetan strands, given the country's century of social and political upheaval.
Even though all cats are similar in appearance, it is difficult to trace the ancestry of individual breeds.
The government's aid to the settlements is difficult to trace because much of it moves through complex bureaucratic conduits or is hidden in vaguely described budget items.
It is difficult to trace this type of attack because the individuals behind them use dozens of computers they have hijacked.
