39th Annual Meeting of the European-Association-for-the-Study-of-the-Liver, Berlin, Almanya, 14 - 18 Nisan 2004, ss.167
We evaluate theoretical uncertainties to the method of Pais and Treiman to measure the $\pi\pi$ phase shifts in $K_{e4}$ decays. We find that they are very small, below $1\%$.