\documentclass[letterpaper,10pt]{article}
\usepackage{biblatex} %Imports biblatex package
\addbibresource{sample.bib} %Import the bibliography file
\begin{document}
Let's cite! Einstein's journal paper \cite{einstein} and Dirac's book \cite{dirac} are physics-related items.
\printbibliography %Prints bibliography
\end{document}