Karpova: This game was annotated by S R Wolf.
According to Wolf, 4.Ne2 is necessary because of <4...dxe4 5.fxe4 Qh4!>.
After 4...c5, Wolf notes that the game is now a French with White having won the move f3.
Wolf awards 19.gxf5 a <?>, calling the move overhasty. He suggests to first double ♖s on the g-file. I wonder if maybe 18.g4 was overhasty, allowing 18...Nb4.
On 21...Bh5, Wolf notes that black now gets a counterattack, which he keeps going for about 20 moves.
23.Qb2 is called necessary due to the threat <23...Bxe2 24.Bxe2 Nxe5>.
49.f5<!>
52.Nc3: To cover the ♕d1 and so, indirectly, the ♙e5.
53.Rd2<!>
On 65...f4, Wolf notes that black constantly plays for a win. This move seems to be a mistake, though. Both contestants seem to have missed 66.Rd5+ (66...Kg6 67.Qd7).
Source: 'Österreichische Schachrundschau', January 1922, issue 1, pp. 5-6