Is <nl> valid HTML? I've not seen it used before. Depending on your browser, it may not display anything in between those tags. (It does for me on Netscape 4.crashcrash2 on Linux.)

If you switch to CGI.pm as Ovid suggests, you can test your script from the command line -- highly recommended. I'd also change your loop to this (personal preference):

for ($firstDisp .. $lastDis) {
print "<li>" . $matchBooks[$_][2] . ".<br>" 
    . $matchBooks[$_][3] . "." . $matchBooks[$_][8] . "<br>"
    . $matchBooks[$_][4] . "." . $matchBooks[$_][6]
    . "</li>";
}
[download]

It's ugly, but I test that way just to be sure that my complex data structure elements print out correctly. (I go back later and fix it.)