After the discovery of important formulae connecting Kloosterman sums with non-holomorphic modular forms by Kuznetsov in 1979, which contained some 'savings on average' over the square root estimate, there were further developments by Iwaniec and Deshouillers in a seminal paper in Inventiones Mathematicae (1982).
Sum 41 | The Sum of All Fears | Yeung Sum | The Sum of All Fears (film) | Sum Mo Chikan | The Sum of Us | Sum-of-squares optimization | Sum of absolute transformed differences | Motivation (Sum 41 song) | lump sum | J C Sum | Dim sum | civis romanus sum | Chebyshev's sum inequality |