The earliest bubble-tunneling vacuum decay paper that I know of is
Bubbles in Metastable Vacuum
I.Yu. Kobzarev, L.B. Okun, M.B. Voloshin (Moscow, ITEP)
Oct 1974 - 16 pages
Sov.J.Nucl.Phys. 20 (1975) 644-646
Yad.Fiz. 20 (1974) 1229-1234
I have also to blow my own trumpet a bit and claim that I independently came up with vacuum-decay bubbles in
Very late answer, but it may be Kerson Huang "Statistical Mechanics" fig. 4.7 pag. 89 (in second edition).
The dots are to evidence the local maxima in time, related to states of molecular chaos of the gas. The theory states that a system with a distribution function $f$ that satisfies Boltzmann's transport equation tends to diminish its $H(f)$ ...
The wikipedia page cites Bloch's paper "Nuclear induction" in 1946 where he wrote down Bloch's equation for nuclear magnetization. It seems that Bloch didn't explicitly say anything about "his sphere", or anything about geometric representation of quantum states of spin-1/2. He went straight to the equation of motion for the magnetization ...