Mathematicians great and not so great have been trying to
crack this nut ever since Riemann put it out there.
Not exact matches
I'm a firm believer that men need to be able to take on more responsibility at home if we're
ever going to
crack this
nut.
But even with what are arguably the best - looking, best - engineered models
ever from Alfa, increasing sales in North America looks like a tough
nut to
crack.
Ever since it came out of stealth mode, FF has been a tough
nut to
crack.