("Title of the page", n.d.a) and
("Title of the page", n.d.b) would combine:
- naming the title in quotation marks
"Article Title" due to the unavailability of an author; and
n.d. (no date) due to the unavailable date; and
- the letter that is added to the date because of multiple same-titles and same-dates (
However, your case is special as the first link is a Wiki. As Geoffrey Brent wrote in a comment, in case of a Wiki, you can click on "View history" and find a permalink to an article's current version with a date attribution. You can then link to that versioned permalink with the date. Here is an example of a version history page pertaining to your first link; the permalink to the most recent version (Feb. 2019) is this one: https://www.sourcewatch.org/index.php?title=Institute_for_Free_Speech&oldid=745869 (you can find this link by clicking on the most recent date listed in the version history page).