which discussed their various contributions. Watson clarified the importance of the data obtained from the MRC report as he had not recorded these data while attending Franklin's lecture in 1951. The upshot of all this was that when Crick and Watson started to build their model in February 1953 they were working with critical parameters that had been determined by Franklin in 1951, and which she and Gosling had significantly refined in 1952, as well as with published data and other very similar data to those available at King's. It was generally believed that Franklin was never aware that her work had been used during construction of the model, but Gosling asserted in his 2013 interview that, "Yes. Oh, she did know about that." Recognition of her contribution to the model of DNA Upon the completion of their model, Crick and Watson had invited Wilkins to be a co-author of their paper describing the structure. Wilkins turned down this offer, as he had taken no part in building the model. He later expressed regret that greater discussion of co-authorship had not taken place as this might have helped to clarify the contribution the work at King's had made to the discovery. There is no doubt that Franklin's experimental data were used by Crick and Watson to build their model of DNA in 1953. Some, including Maddox, have explained this citation omission by suggesting that it may be a question of circumstance, because it would have been very difficult to cite the unpublished work from the MRC report they had seen. Indeed, a clear timely acknowledgment would have been awkward, given the unorthodox manner in which data were transferred from King's to Cambridge. However, methods were available. Watson and Crick could have cited the MRC report as a personal communication or else cited the Acta articles in press, or most easily, the third Nature paper that they knew was in press. One of the most important accomplishments of Maddox's widely acclaimed biography is that Maddox made a well-received case for inadequate acknowledgement. "Such acknowledgement as they gave her was very muted and always coupled with the name of Wilkins". Fifteen years after the fact, the first clear recitation of Franklin's contribution appeared as it permeated Watson's account, The Double Helix, although it was buried under descriptions of Watson's (often quite negative) regard towards Franklin during the period of their work on DNA. This attitude is epitomized in the confrontation between Watson and Franklin over a preprint of Pauling's mistaken DNA manuscript. Watson's words impelled Sayre to write her rebuttal, in which the entire chapter nine, "Winner Take All" has the structure of a legal brief dissecting and analyzing the topic of acknowledgement. Sayre's early analysis was often ignored because of perceived feminist overtones in her book. Watson and Crick did not cite the X-ray diffraction work of Wilkins and Franklin in their original paper, though they admit having "been stimulated by a knowledge of the general nature of the unpublished experimental results and ideas of Dr. M. H. F. Wilkins, Dr. R. E. Franklin and their co-workers at King's College London". In fact, Watson and Crick cited no experimental data at all in support of their model. Franklin and Gosling's publication of the DNA X-ray image, in the same issue of Nature, served as the principal evidence: Nobel Prize Franklin was never nominated for a Nobel Prize. Her work was a crucial part in the discovery of DNA's structure, which along with subsequent related work led to Francis Crick, James Watson, and Maurice Wilkins being awarded a Nobel Prize in 1962.