The former isn't even a new proof: https://arxiv.org/abs/0708.1362 https://arxiv.org/abs/0708.1362 https://www.tandfonline.com/doi/abs/10.4169/amer.math.month

The former isn't even a new proof: https://arxiv.org/abs/0708.1362 https://arxiv.org/abs/0708.1362 https://www.tandfonline.com/doi/abs/10.4169/amer.math.monthly.121.06.498 https://www.tandfonline.com/doi/abs/10.4169/amer.math.monthl...