The internet has become a behemoth of information capacity. It is said that the internet contains many times the information the fabled Library of Alexandria once possessed. Of course, that is an abstract idea. Instead, consider that as of 2009, there was enough data on the internet to fully load 339 miles worth of iPads stacked on top of each other.

Such widely available information is a fantastic thing on all accounts. People in poorer nations can use the internet to learn about farming and how to sustain a clean source of water. Citizens from all the countries of the world can use the web to connect with long lost friends and family members. The internet, by and large, is a tool for discovery and learning.

Of course, the very same thing that makes the internet so wonderful is what makes it difficult to use for students, academics, and professionals in a wide variety of fields. Put simply, there is sometimes too much non-scholarly information to wade through. That is why quality sources of online reference material are so important. If you are a student of history, the sciences, or otherwise, here are three places to find online articles to help in your research.

• Google Scholar

Google Scholar is not in itself a database for reference material online. Instead, it is a specialized search engine meant to make it easier for students and professionals to find information pertinent to their topic. For instance, say you are researching string theory. Google Scholar will only search scholarly articles on the subject, weeding out the rest of the web. Many of the sources Scholar finds are complete and free, while others require a subscription or outright purchase.

• JStor

JStor is used by students across the world as a quality source of online info for a wide variety of disciplines. Unlike Google Scholar, JStor is its own database. Each item that is logged into the system is reviewed and authenticated before being admitted, ensuring its quality for every reader. While in college, students are likely to receive unlimited access to JStor. However, its downside is found in the fact that it requires a subscription when you are no longer a student, and that can be quite costly.

• The Directory of Open Access Journals

The Directory of Open Access Journals provides scholars with a means of accessing many high quality scholarly journals without having to pay a fee. The DOAJ subsists only on donations from generous users and those that believe in their cause. Like JStor, DOAJ maintains its own databases that are kept to a certain standard of quality. However, unlike other sources for academic journals, DOAJ requires no payment.

The next time you are looking for online reference material, keep these three sites in mind. They each have benefits, pros and cons. However, they all have the ability to make your search for online reference materials far easier than a general search.