Ambartsumian and Ivanenko (1930) "Об одном следствии теории дирака протонов и электронов" (On a Consequence of the Dirac Theory of Protons and Electrons), Доклады Академии Наук СССР (Doklady Akademii Nauk SSSR / Proceedings of the USSR Academy of Sciences) Ser. A, no. 6, pages 153-155. Available in Russian on-line.
Nakamura, K (2010). “Review of Particle Physics”. 《Journal of Physics G: Nuclear and Particle Physics》 37 (7A): 075021. Bibcode:2010JPhG...37g5021N. doi:10.1088/0954-3899/37/7A/075021.PDF with 2011 partial update for the 2012 editionThe exact value of the mean lifetime is still uncertain, due to conflicting results from experiments.The Particle Data Group reports values up to six seconds apart (more than four standard deviations), commenting that "our 2006, 2008, and 2010 Reviews stayed with 885.7±0.8 s; but we noted that in light of SEREBROV 05 our value should be regarded as suspect until further experiments clarified matters. Since our 2010 Review, PICHLMAIER 10 has obtained a mean life of 880.7±1.8 s, closer to the value of SEREBROV 05 than to our average. And SEREBROV 10B[...] claims their values should be lowered by about 6 s, which would bring them into line with the two lower values. However, those reevaluations have not received an enthusiastic response from the experimenters in question; and in any case the Particle Data Group would have to await published changes (by those experimenters) of published values.At this point, we can think of nothing better to do than to average the seven best but discordant measurements, getting 881.5±1.5s. Note that the error includes a scale factor of 2.7. This is a jump of 4.2 old (and 2.8 new) standard deviations. This state of affairs is a particularly unhappy one, because the value is so important. We again call upon the experimenters to clear this up."
Bothe, W.; Becker, H. (1930). “Künstliche Erregung von Kern-γ-Strahlen” [Artificial excitation of nuclear γ-radiation]. 《Zeitschrift für Physik》 66 (5–6): 289. Bibcode:1930ZPhy...66..289B. doi:10.1007/BF01390908.
Becker, H.; Bothe, W. (1932). “Die in Bor und Beryllium erregten γ-Strahlen” [Γ-rays excited in boron and beryllium]. 《Zeitschrift für Physik》 76 (7–8): 421. Bibcode:1932ZPhy...76..421B. doi:10.1007/BF01336726.
Chadwick, J. (1933). “Bakerian Lecture. The Neutron”. 《Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences》 142 (846): 1. Bibcode:1933RSPSA.142....1C. doi:10.1098/rspa.1933.0152.
Nakamura, K (2010). “Review of Particle Physics”. 《Journal of Physics G: Nuclear and Particle Physics》 37 (7A): 075021. Bibcode:2010JPhG...37g5021N. doi:10.1088/0954-3899/37/7A/075021.PDF with 2011 partial update for the 2012 editionThe exact value of the mean lifetime is still uncertain, due to conflicting results from experiments.The Particle Data Group reports values up to six seconds apart (more than four standard deviations), commenting that "our 2006, 2008, and 2010 Reviews stayed with 885.7±0.8 s; but we noted that in light of SEREBROV 05 our value should be regarded as suspect until further experiments clarified matters. Since our 2010 Review, PICHLMAIER 10 has obtained a mean life of 880.7±1.8 s, closer to the value of SEREBROV 05 than to our average. And SEREBROV 10B[...] claims their values should be lowered by about 6 s, which would bring them into line with the two lower values. However, those reevaluations have not received an enthusiastic response from the experimenters in question; and in any case the Particle Data Group would have to await published changes (by those experimenters) of published values.At this point, we can think of nothing better to do than to average the seven best but discordant measurements, getting 881.5±1.5s. Note that the error includes a scale factor of 2.7. This is a jump of 4.2 old (and 2.8 new) standard deviations. This state of affairs is a particularly unhappy one, because the value is so important. We again call upon the experimenters to clear this up."
Bothe, W.; Becker, H. (1930). “Künstliche Erregung von Kern-γ-Strahlen” [Artificial excitation of nuclear γ-radiation]. 《Zeitschrift für Physik》 66 (5–6): 289. Bibcode:1930ZPhy...66..289B. doi:10.1007/BF01390908.
Becker, H.; Bothe, W. (1932). “Die in Bor und Beryllium erregten γ-Strahlen” [Γ-rays excited in boron and beryllium]. 《Zeitschrift für Physik》 76 (7–8): 421. Bibcode:1932ZPhy...76..421B. doi:10.1007/BF01336726.
Chadwick, J. (1933). “Bakerian Lecture. The Neutron”. 《Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences》 142 (846): 1. Bibcode:1933RSPSA.142....1C. doi:10.1098/rspa.1933.0152.
Nakamura, K (2010). “Review of Particle Physics”. 《Journal of Physics G: Nuclear and Particle Physics》 37 (7A): 075021. Bibcode:2010JPhG...37g5021N. doi:10.1088/0954-3899/37/7A/075021.PDF with 2011 partial update for the 2012 editionThe exact value of the mean lifetime is still uncertain, due to conflicting results from experiments.The Particle Data Group reports values up to six seconds apart (more than four standard deviations), commenting that "our 2006, 2008, and 2010 Reviews stayed with 885.7±0.8 s; but we noted that in light of SEREBROV 05 our value should be regarded as suspect until further experiments clarified matters. Since our 2010 Review, PICHLMAIER 10 has obtained a mean life of 880.7±1.8 s, closer to the value of SEREBROV 05 than to our average. And SEREBROV 10B[...] claims their values should be lowered by about 6 s, which would bring them into line with the two lower values. However, those reevaluations have not received an enthusiastic response from the experimenters in question; and in any case the Particle Data Group would have to await published changes (by those experimenters) of published values.At this point, we can think of nothing better to do than to average the seven best but discordant measurements, getting 881.5±1.5s. Note that the error includes a scale factor of 2.7. This is a jump of 4.2 old (and 2.8 new) standard deviations. This state of affairs is a particularly unhappy one, because the value is so important. We again call upon the experimenters to clear this up."
Mohr, P.J.; Taylor, B.N. and Newell, D.B. (2011), "The 2010 CODATA Recommended Values of the Fundamental Physical Constants" (Web Version 6.0). The database was developed by J. Baker, M. Douma, and S. Kotochigova. (2011-06-02). National Institute of Standards and Technology, Gaithersburg, Maryland 20899.