or download this
my $str = "<P_contrib-author>Mariel Miller</P_contrib-author>,<P_contr
+ib-author>Allyson Fiona Hadwin</P_contrib-author>,<P_contrib-author>J
+enna Cambria</P_contrib-author>";
...
print '<alt-title alt-title-type="running-head-verso">',
join( ", ", @authours ),
'</alt-title>';