regions are: North America, Europe, Asia, South America, Oceania,
Africa, Central America.
</p>
<p>The years are: 1951, 1956, 1957, 1958, 1959, 1960, 1961.
</p>
<h4 class="subsubheading" id="Source-83"><span>Source<a class="copiable-link" href="#Source-83"> &para;</a></span></h4>

<p>AT&amp;T (1961) <cite class="cite">The World’s Telephones</cite>.
</p>
<h4 class="subsubheading" id="References-46"><span>References<a class="copiable-link" href="#References-46"> &para;</a></span></h4>

<p>McNeil, D. R. (197