\documentclass{article}
\usepackage{amssymb,amsmath,latexsym}

\newtheorem{theorem}{Theorem}
\newtheorem{definition}{Definition}
\newtheorem{lemma}{Lemma}
\newtheorem{corollary}{Corollary}
\newtheorem{proposition}{Proposition}  % proof environment?

\begin{document}

\title{titleline1\\
  titleline2}
\author{author's name\thanks{support from source}\\
  addressline1\\
  addressline2}
\date{date}
\maketitle

\begin{abstract}
  abstract here
\end{abstract}

\section{section name}
section text.

\section{section name}
section text.

\begin{theorem}
  There exists a theorem.
\end{theorem}
\emph{Proof.}
By inspection.

\begin{thebibliography}{9}
  \bibitem{labelname1}
    author,
    \emph{title},
    source.  \textbf{volume\#} (date), page1--pageN.
  \bibitem{labelname2}
    author,
    \emph{title},
    source.  \textbf{volume\#} (date), page1--pageN.
\end{thebibliography}

\end{document}