Note: Conservatism of the Approximation Σ(O - E) 2 /E in the Logrank Test for Survival Data or Tumor Incidence Data

Richard Peto, M. C. Pike, 352. Note: Conservatism of the Approximation (O - E) ²/E in the Logrank Test for Survival Data or Tumor Incidence Data, Biometrics, Vol. 29, No. 3 (Sep. , 1973), pp. 579-584