Blast From The Past

GOING through old notes, I came across a very interesting pawn ending.

It is White to make his 34th move, but what should the result be?

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Material is level. White has more space on the kingside and, theoretically at least, in the centre; Black has more space on the queenside and his king is more advanced. Both players have a reserve tempo - g2-g3 for White, h7-h6 for Black.
The game was won by Black:
34.g3 c5 35.dxc5 c6?
Over-elaboration. The obvious 35...Kxc5 wins.
36.Ke3?
All king moves clearly lose, so White should have tried the only other possible move, 36.c4, which draws after 36...bxc4+ 37.Ke3 Kxc5 38.c3, when Black has no way into White's position.
36...Kc4 37.Kd2 h6 38.Kd1 Kxc3 Leo Keely (174) - Spanton (173), Hastings Challengers' 1998-99 (0-1, 42 moves)
Going back to the diagram, White had a draw: 34.c4+! bxc4+ 35.Ke3, eg 35...c5 36.dxc5 Kxc5 37.c3.
A little earlier in the game, there was a position in which analysis engines point out two possible draws for White.

White to make his 33rd move

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33.c4+ draws in a similar fashion to the line already given, but with the nuance that Black can try (unsuccessfully) to penetrate with his king down the a file, eg 33...bxc4+ 34.Ke3 c5 35.dxc5 Kxc5 36.c3 Kb5 37.Kd2 Ka4 38.Kc2 Ka3 39.Kb1. and White holds.
Even better for White, because it gives Black a plausible losing chance, is 33.a4+!, eg 33...bxa4? 34.c4+ Kd6 35.c5+ Kd7 (not 35...Kd5?? 36.c4#) 36.Kc3 etc.
However, Black draws easily enough, eg 33...h6 34.g3 Kd6 35.c4 b4 - an only move, but now it is White who cannot make progress, eg 36.Ke4 c5 37.d5, and Black can even play the cheeky 37...b3!? and still draw.