proper syntax of getting wp-admin pages/links

Question

i cant seem to find the codex for my situation.

normally, i use get_bloginfo('template_url') to get to the template path, but this time i need to get to some WP-ADMIN pages.

i created a custom navigation bar on my wp-admin and everything is working fine. i just need to get the links for the ff:

• /wp-admin/upload.php
• /wp-admin/index.php
• /wp-admin/edit.php?post_type=page

what is the proper syntax getting the path to these locations

get_bloginfo('admin_url')/wp-admin-upload.php // sample only, just to express my point.