You can search by keyword in any agency collection. Here's the sales tax search in the Legislative Assembly collection
You can also use the search box at Oregon.gov, or use Google or other search engines.
Oregon State Library Digital Collections also includes collections for maps, Oregoniana, and federal documents, so be sure to explore!
What about federal goverment publications?
The State Library is also a Federal Depository Library. You can access federal government publications through the online catalog, using searches similar to those you'd use for Oregon government publications. Visit our Federal Government Information page for more tips about searching federal government publications.