Sierakowski R, Finlayson B, Landes R
Urol Res. 1979 Sep;7(3):157-60. doi: 10.1007/BF00257200.
A survey of 1974 discharge data from United States hospitals shows an apparent increase in urolithiasis. A negative correlation has been found between the geographical distribution of the relative frequency of hospital discharges, a diagnosis of urolithiasis, and reported water hardness.