Sentence examples for been difficult to attain from inspiring English sources

Vaccination of older children is considered effective by most experts, but high vaccination coverage of these subjects has been difficult to attain.

Unanimity among the electoral princes had always been difficult to attain; hence the validity of election by majority vote, a principle already set forth in the Declaration of Rhens, was reaffirmed.

The accuracy obtained for energy barriers by Claeyssens et al. is unprecedented for enzyme reactions, and has been previously been difficult to attain even for small molecules.

This prohibition has kept law firms from being able to tap the venture capital or equity markets, leaving them dependent on debt financing, which has been difficult to attain in the current environment.

Although large collections of chemical data have recently become represented in RDF and exposed to SPARQL querying [11 13], seamless and facile integration of computational resource output to enable query completion has been difficult to attain with currently existing technologies.

Consensus has been difficult to attain because of incomplete and conflicting data from various regions throughout the world.

This equilibrium is difficult to attain and even more difficult to change.

But he conceded it would be difficult to attain that goal.

An empirically grounded, universally valid judgment on the impact of e-cigarettes may be difficult to attain.

In fact ηa is shown to be limiting, such that values over ηa > 50% are difficult to attain.

Due to the relatively thin concrete panel thickness, it is difficult to attain adequate ductility in connection system.