Oregon doesn’t have a lot of options when it comes to researching Oregon RICO laws in secondary sources. (Legal secondary sources are awash with articles, essays, commentary, etc. on federal and other state’s RICO law and practice.)
There is, however, a chapter on Oregon RICO law in this book, “RICO state by State,” 1998 edition, starting on page 739.
1) Try this direct Google Books link to see a chapter from the 1998 edition.
2) If that doesn’t work, search Google with this search: rico state litigation. It should be one of the first items, the book by John Floyd. See page 739 for Oregon. (The Contents page won’t say Oregon. Just look for page 739.)
3) Also, see the RICO Law Blog.
4) There are also, of course, the usual primary sources research resources: statutes, cases, etc.