This gives an overview of enclosure josekis (that is, joseki that start with a shimari rather than a single stone) that have a page (or several pages) on Sensei's Library, grouped by original enclosure.
See also invading and reducing around enclosures, Enclosure josekis - the book.
3354 enclosure
3554 enclosure
A large number of other enclosures is discussed (with links) on Unusual Enclosures