How to change bibliography name in article

Question

I need to change my bibliography name in "Bibliografia essenziale", I have tried that but it doesn't work

\documentclass[a4paper, oneside, openright]{article}
\pdfpagewidth\paperwidth
\pdfpageheight\paperheight
\usepackage[utf8]{inputenc} 
\usepackage[italian]{babel}
\usepackage[T1]{fontenc}
%usepackage{lipsum}
\usepackage{lmodern}
\usepackage{graphicx}
\usepackage{indentfirst}
\usepackage{amssymb}
\usepackage{amsmath} 
\usepackage{latexsym}
\usepackage{amsthm} 
\usepackage{caption}
\usepackage{eucal} 
\usepackage{eufrak} 
\usepackage[hidelinks]{hyperref}
\usepackage{verbatim}
\usepackage{mathtools}
\usepackage{mathrsfs}
\usepackage{enumerate}
\usepackage{pgfplots}
%\usepackage{lipsum}
\usepackage{wrapfig}
\usepackage{float}
\usetikzlibrary{intersections}
\tikzset{point/.style={insert path={node[circle,inner sep =1.5 pt,fill]{}}}
}
\usepackage{listings}
\usepackage{color}
\theoremstyle{plain} 
\newtheorem{thm}{Teorema}[section] 
\newtheorem{cor}[thm]{Corollario} 
\newtheorem{lem}[thm]{Lemma} 
\newtheorem{prop}[thm]{Proposizione}
\theoremstyle{definition} 
\newtheorem{defn}[thm]{Definizione}
\theoremstyle{remark} 
\newtheorem{oss}[thm]{Osservazione}
\newtheorem{esem}[thm]{Esempio}
\title{\begin{huge}
\textbf{...}
\end{huge}}
\date{\vspace{-5ex}}
\author{...\ ...}
\begin{document}
\maketitle
...
\vspace{1 cm}
\nocite{*}
\bibliographystyle{alpha}
\bibliography{Bibliografia}
\renewcommand{\refname}{Bibliografia essenziale}
\end{document}

This is my file Bibliografia.bib

@book {Bhatia,
    AUTHOR = {Bhatia, Rajendra},
     TITLE = {Matrix analysis},
    SERIES = {Graduate Texts in Mathematics},
    VOLUME = {169},
 PUBLISHER = {Springer-Verlag, New York},
      YEAR = {1997},
     PAGES = {xii+347},
      ISBN = {0-387-94846-5},
   MRCLASS = {15-02 (47-02)},
  MRNUMBER = {1477662},
MRREVIEWER = {R. J. Bumcrot},
       DOI = {10.1007/978-1-4612-0653-8},
       URL = {https://doi.org/10.1007/978-1-4612-0653-8},
}

Can someone help me?