I'm reading a .pdf file about Probability. Here's the link
The author introduces the lemma 4.1, suggesting to consult the proof in a specific book. I tried to search the lemma in the book but i didn't find it. Please help me to find a name for this lemma so as i can consult its proof...
Lemma 4.1. Let $Z_1, Z_2, \dots$ be a sequence of random variables having distribution functions $F_{Z_n}$ and moment generating functions $M_{Z_n}$ s.t. $n \geq 1$. Furthermore, let $Z$ be a random variable having distribution $F_Z$ and moment generating function $M_Z$. If $M_{Z_n}(t) \to M_Z$ for all $t$, then $F_{Z_n}(t) \to F_{Z}(t)$ for all $t$ at which $F_Z(t)$ is continuous.