Westlaw, available to Stanford Law School users by personal name and password, has 50 state surveys available on a variety of statutory and regulatory topics.
To access the surveys, type "50 state surveys" in the search box. Then select "50 State Surveys" under "Content Pages." If you know whether your content is statutory or regulatory you can fine tune your results by selecting 50 State Statutory Surveys or 50 State Regulatory Surveys.

Next, you can run a search across the filtered secondary sources.
