It is difficult to ascertain whether this strategy has been successful.
It's difficult to ascertain whether efforts aimed directly at consumers ultimately translate into real sales.
It may sometimes be difficult to ascertain whether a transfer of copyright is voluntary or is coerced by covert pressure.
This is because it may be difficult to ascertain whether wanting to be a girl is merely a passing game, or something that won't leave him.
It is also difficult to ascertain whether he was influenced by working with other contemporary artists or merely by viewing prints of their work.
The Palsars are maneuvering amid a population that overwhelmingly views them as the enemy, and they are finding it increasingly difficult to ascertain whether they are winning -- or even to calculate what "victory" would mean.
It is often difficult to ascertain whether the same composer created both the words and the music in a folk song; many songs are known to have separate sources for words and music.
For other parameters, it is difficult to ascertain whether the influence is a determinant of the siRNA per se, or a determinant of the target RNA, especially its local structural characteristics.
Without a shared definition of success, it's difficult to ascertain whether success was ever achieved.
It is difficult to ascertain whether these lectures were given at the Union Institute, Normal College or Trinity College.
Cause of death was difficult to determine in virtually all turtles recorded and it is difficult to ascertain whether observed external injuries were obtained post-mortem.
