The phrase 'difficulty to distinguish' is correct and can be used in written English.
For example: Due to the limited information available, it is difficult to distinguish between what is true and what is false.
Again, the reason might be the difficulty to distinguish cello from other string instruments.
However, there is still a difficulty to distinguish the fringes caused by OH lines from the OI (630.0 nm) fringes.
A general issue of studies using aggregated industry data is the difficulty to distinguish between factor substitution and concurrent effects.
Perhaps it's the difficulty to distinguish oneself in the category — operating systems aside, Samsung's Gear devices and the Apple Watch largely offer the same feature set.
This highlights the difficulty to distinguish between the effects of heparin nebulization and other parts of treatment on patient outcome in retrospective studies with historical controls.
Over lands, the cloud detection on remote sensing images is not an easy task, because of the frequent difficulty to distinguish clouds from the underlying landscape, even at a high resolution.
Although the lack of ESTs in particular tissues may indicate difficulties to distinguish between different MT1 transcripts or bias in tissue representation, these caveats do not necessarily challenge the tissue-specificity generally observed in most MT1 duplicates, possibly playing distinct roles in distinct cell types as was suggested before [44], [46].
However, these studies differed in the methodology and markers used to define Tregs, underscoring difficulties to distinguish allergen-specific Tregs.
Lower respiratory tract infections like acute bronchitis, exacerbated chronic obstructive pulmonary disease and community-acquired pneumonia are often unnecessarily treated with antibiotics, mainly because of physicians' difficulties to distinguish viral from bacterial cause and to estimate disease-severity.
The GIPD was therefore designed both to capture ADHD-related difficulties and to distinguish between various times of the day.
