Go to the View menu.
Choose Hide Invisibles.
The dots show you where the spaces are. I'd delete the one before Manipulation in the second line.
The pilcrow ( ¶ ) shows where you pressed return.
Down in the References, you pressed tab three times after "228-269". I can see why you might have wanted to avoid splitting the publisher name, but not why you'd want this to be the only indented second line in the references.
Showing invisibles can be a handy tool when you are cleaning up a document. It's done using the same menu item (which toggles between Hide and Show, depending on the current status). The keystroke shortcut for this item is listed in my menu as shift-command-I, so it's possible you may have pressed that.
Regards,
Barry