A common reason that pages are not appearing in search results is the presence of the attribute in page links. This attribute tells crawlers to not follow the link and to not record its contents. In short, if a link contains , search cannot access it.
Many link generators will include this attribute, either by default or as an option you can select. If a certain page is not showing in results for you, visit a page where it is linked to and see if is present. If it is, edit the link and contact [email protected] to recrawl your site.
For more information about the nofollow attribute, please refer to Google's article Use for specific links