Nonetheless, the watershed events, which would come to denote the era of first quantization, took place in the vital years spanning 1925–1928. Simultaneously the authors Born and Jordan in December 1925, together with Dirac also in December 1925, then Schrodinger in January 1926, following that, Born, Heisenberg and Jordan in August 1926, and finally Dirac in 1928. The results of these publications were 3 theoretical formalisms 2 of which proved to be equivalent, that of Born, Heisenberg and Jordan was equivalent to that of Schrodinger, while Dirac's 1928 theory came to be regarded as the relativistic version of the prior two. Lastly, it is worth mentioning the publication of Heisenberg and Pauli in 1929, which can be regarded as the first attempt at " second quantization ", a term used verbatim by Pauli in a 1943 publication of the American Physical Society.