The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
The issue itself carries the date: the paper was "published by Francis Crick and James D. Watson in the scientific journal Nature on pages 737-738 of its 171st volume (dated 25 April 1953)", and Nature's own page for the article gives the same issue date.
Gives the journal, volume, pages and issue date, and describes the method - X-ray diffraction and the mathematics of a helix transform - and why the paper is called a "pearl" of science.[1]
The Cambridge physics department where Watson and Crick built the model, and where this pin is placed; the old laboratory on Free School Lane.[1]
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most.