Today, this is largely ineffective both because press releases generally use nofollow links, which make them less effective for SEO, and because Google has devalued this tactic algorithmically. (searchenginejournal.com)
Because Wikipedia uses nofollow tags, external links do not alter search engine rankings. (en.wikipedia.org)
Do not use nofollow when linking to internal pages in your website. (squaremedia.solutions)