Could you please provide a link to the source? $$\sum_{\chi\neq \chi_0}\int_{0}^{T}|L(1/2+it,\chi)|^4dt\ll (qT)^{1+\varepsilon},$$ where $\chi_0$ is the principal character modulo $q$, and $L(s,\chi)$ is the Dirichlet L-function associated to $\chi$
P.S. I found only for primitive characters, but I need for non-principal characters.