When searching via Google, you can get better results by restricting results to a type of site or a type of document. For example, if you know that the results you want would be found on a government site, include the Google syntax with the government website extension – site:gov. If you want the result to be a particular file format like Excel, include the Google syntax filetype: with the extension for Excel – xls. Thus, filetype:xls would be what you would add to the search string.
Knowing where to look is more than half the battle. One place to find good research guides is on the Law Library of Congress website. The URL always has loc.gov in it. If I want to find a research guide on labor law in Vietnam, I would make this search query Vietnam labor law research guide site:loc.gov -veteran. The -veteran excludes results about Vietnam era veterans. The terms go from left to right in order of importance. I believe Google will return results for both labor and labour, but you should be aware of the two spellings and make sure it does return both results with just one of these words.
Another type of site that has good research guides are law school libraries. Such sites have the extension edu and the search query should include the word law in it. Thus, one could use the same query as above but substitute edu for loc.gov.