my $replace = sub { 
	push @findmissing, "$bookabbrev\t$1\t$2\t$3\n"; 
	return '' 
	};

foreach (0..$#missingpages) { 
	chomp $missingpages[$_];
	my $skipped=$missingpages[$_];
	my $before=qq|<a id="$bookabbrev\_|.($skipped-1).qq|">|;
	my $after=qq|<a id="$bookabbrev\_|.($skipped+1).qq|">|;

s/$before.*?(.{0,25})(?<!\d)($missingpages[$_])(?>\D)(.{0,25}).*?$after/$replace->()/eg for @source;
}