Link to Google's advanced search page
In addition to the aforementioned link you can also search for something then above your search result click on "Search tools" this will invoke drop down menus that will aid in narrowing down the results.
This will search for peer-reviewed scholarly literature. Searching for penguins will not yield cute desktop pictures but will yield results on sphenisciform seabirds.
After you peruse DHMO.org contact Nathan in the LITe department to find out more about DHMO and why it was included here.