Primary source: www.bmj.com/content/2/5159/1041
Verified locator: BMJ 2(5159), 1041–1046, 21 November 1959; DOI 10.1136/bmj.2.5159.1041; PMID 13846051. Primary publisher bylines B. M. Wright and C. B. McKerrow. The PubMed title includes the subtitle describing a new portable instrument. Basil Martin Wright identity is directly corroborated by the Wood Library-Museum object catalogue author field, not inferred from initials.