Administrator rights also for “normal” user

I have several Plugins installed and the preferences of these plugins are available in the options menu on the left side of the dashboard when I’m logged in as an admin. When I log in with another user who has author rights, the preferences of the plugins are not visible on the left side in my dashboard. How can I allow authors to see the preferences of the plugins?

btw: I also installed the role manager plugin and the user group “author” have all available rights but still then they can’t see the preferences. Only user with original administrator rights can see the additional plugin preferences in the option part of the left-side dashboard menu…