The Generalization of Student's Problem when Several Different Population Variances are Involved by Bernard Lewis Welch (1947)

By Bernard Lewis Welch. Biometrika 34(1–2), 28–35. The original title puts Student in quotation marks. Publisher title/byline/date verified at academic.oup.com/biomet/article-abstract/34/1-2/28/210174 . Author paper scan: www.dcscience.net/welch-1947.pdf . The browser retrieved the scan but did not extract its text; the biographical citation uses the publisher-verified title and journal record.