Offprints by Posten and Sheynin Offprints of "The Robustness of the Two-Sample t-test Over the Pearson System" (1977) and "The Robustness of the One-Sample t-test Over the Pearson System" (1978) both by Harry O Posten; "On the Mathematical Treatment of Observations by L. Euler" (1972) and "On the Prehistory of the Theory of Probability" (1974) both by O B Sheynin. 1972-1978