arivero said:
You can find Dirac papers in the Royal Society journals, free until december,
I do not remember the links. You could try the "online" tag in physcomments.org
http://www.pubs.royalsoc.ac.uk/index.cfm?page=1373
Still the best work to study the Dirac equation are the papers in
which Dirac introduced it:
The Quantum Theory of the Electron.
vol 117, 1 February 1928, pp.610-24
The Quantum Theory of the Electron II
vol 118, 1 March 1928, pp. 351-61
Dirac's start in quantum mechanics is where he, after reading
Heisenberg's paper on Matrix mechanics, introduces the Poisson
brackets from classical dynamics into quantum mechanics:
The fundamental equations of quantum mechanics.
vol 109, 1 December 1925, pp. 642-53
Hard to read without Heisenberg's work though. One might use:
The physical interpretation of the quantum theory:
https://www.amazon.com/dp/0486601137/?tag=pfamazon01-20
for this, see the appendix (which is half the book) Other famous Dirac papers where published elsewhere:
The lagrangian in Quantum Mechanics:
Physikalische Zeitschrift der Sowjetunion, vol 3, n0.1, pp 64-72
The theory of magnetic poles:
The Physical Review, vol 74, no.7, 1 October 1948, pp. 817-30Regards, Hans