Determining the source of information is critical when exploring bias.
When using Lexis-Nexis
For news sources found online, search their website for clues about it's country of origin.
Sources from some countries with political/social unrest may be operating/reporting from outside the country.
Note: BBC Country Profiles allows you to search for media outlets for many countries. Search for your country, then click on the "Media" tab to see a list of media published in that country. You can perform a Google News Archive Search limiting to just those sources.
Or, Limit a newspaper search in Google Advanced to the specific country code of your country of choice.