Wheldon's business statistics and statistical method / G. L. Thirkettle. Wheldon, Harold J. (Harold James) Thirkettle, G. L. (George Leslie) Statistics. Business Statistical methods. 658 19 WHB First ed. published in 1936. Includes index. London : Macdonald & Evans, 1968. 1968. 1968 Text xii, 308 p. : eng