Summarize a topic, edit the summary, then click History in the topic's action menu, then click the timestamp under a "topic summary" change.
The text in here says:
This is a permanent link to a single version of the summary for this post. This version is from 34 minutes ago. You can see the differences from the previous version, or view other versions on the post history page.
Should be "summary of this topic" and "view other versions on the topic history page"
On that topic summary page, e.g.
This page shows the changes between two versions of a post summary in the post "Another test topic" on Talk:Flow. You can see other versions of this post at its history page.
Should be "two versions of the summary for the topic ... You can see other versions of this topic summary at its history page."