title: How to specify multiple source files in Makefile.am
body: <p>New to using <code>autoconf</code> and <code>automake</code>, I am following <a href="https://robots.thoughtbot.com/the-magic-behind-configure-make-make-install" rel="nofollow"> this</a> to learn them. </p>
  
  <p>I have a question regarding <code>Makefile.am</code> file. For a simple <code>helloworld</code> program below <code>Makefile.am</code> works:</p>
  
  <pre><code>AUTOMAKE_OPTIONS = foreign
  bin_PROGRAMS = helloworld
  helloworld_SOURCES = hello.c
  </code></pre>
  
  <p>How do we specify multiple source files (if there are multiple source files required to compile the program) in the third line ? </p>
  
  <p>You can assume all source files are in same directory where the <code>Makefile.am</code> is.</p>