# Writting Letter With Bibliography

## Background

Recently, I need to write letters. Get the formatting for addressee and sender automatically done, I choose $\rm \LaTeX$. I cite a book in my letter, and try to add a bibliography at the end of the letter.

## Problem

During the compilation for the following letter, an error was thrown.

Here’s my compilation procedure.

$xelatex noltrbib.tex$ biber noltrbib