I want to cite some references in my article. (I used \cite{}.) However, it turns out some bold words instead of citation numbers are produced. Here is my code:
\usepackage{url}
\renewcommand{\UrlFont}{\small\tt}
\usepackage{graphicx}
\usepackage{epstopdf}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usepackage{filecontents}
\usepackage[style=verbose]{biblatex}
\usepackage{graphicx}
\graphicspath{ {images/} }
\usetikzlibrary{automata,arrows,positioning,calc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{setspace}
\section{Data}
The data were collected from ITTF \cite{ITTF}.
\begin{thebibliography}{1}
\bibitem{J}
McGarry, T., and Franks, I.M.,
A stochastic approach to predicting competition squash match-play,
\emph{Journal of Sport Sciences}, 1994, 12, 573-584.
\bibitem{l}
Lames, M.
\emph{Leistungsdiagnostik durch Computersimulation. [Performance diagnosis by computer simulation]}.
Frankfurt/Main: Harri Deutsch, 1991, pp. 7-257.
\bibitem{ITTF}
International Table Tennis Federation.
\\\texttt{http://www.ittf.com/}
\end{thebibliography}

documentclassand whatever you need from the preamble, if anything, adocumentenvironment and a\citecommand or two -- it should be a minimal example.) When I add your code snippet in a minimal example of my own it works as expected, so there's something going on that you're not showing us. – Torbjørn T. Nov 30 '16 at 03:46biblatexpackage, which you're not actually using. Remove\usepackage[style=verbose]{biblatex}, delete the.auxfile, and runpdflatexagain. – Torbjørn T. Nov 30 '16 at 04:00