.The paper discusses the contributions Student W. S. Gosset made to the three stages in which small-sample methodology was established in the period 1908–1933: (i) the distributions of the test-statistics under the assumption of normality, (ii) the robustness of these distributions against nonnormality, (iii) the optimal choice of test statistics. The conclusions are based on a careful reading of the correspondence of Gosset with Fisher and E. S. Pearson.
"“Student” and small-sample theory." Statist. Sci. 14 (4) 418 - 426, November 1999. https://doi.org/10.1214/ss/1009212520