author link

I can’t get the author link on the archive page.
For example, when I click archive-october 2009, I get the title “news for october 2009” and the list of it.
I added author lists to my sidebar, clicked it, I get the right list of the author, but not the title with the author name. I modified archive.php to included <?php the_author(); ?> or <?php the_author_posts_link(); ?>, but no success. It looks like none of the author tags works.
Solutions, anybody?