Problem 516

adapted by Hugh Darwen and Steve Bloom from a hand reported by Bart Bramley in Bridge World, December 2011

DR6	♠ 96 ♥ 7654 ♦ AKQJ109 ♣ 7
♠ K7532 ♥ K ♦ 432 ♣ AKQ10		♠ none ♥ Q1032 ♦ 765 ♣ J65432
	♠ AQJ1084 ♥ AJ98 ♦ 8 ♣ 98

What lead or leads will set four spades by South?  
How is the contract made on any other lead?