1<p class="Pp"><span class="Rs"><span class="RsA">Brian W. Kernighan</span> and 2 <span class="RsA">Lorinda L. Cherry</span>, “<cite class="RsT">System 3 for Typesetting Mathematics</cite>”, <i class="RsJ">Communications of 4 the ACM</i>, <span class="RsV">18</span>, <span class="RsP">pp. 5 151–157</span>, <span class="RsD">March 1975</span>.</span></p> 6