Reference sources are usually most valuable at the beginning of a research project. They can provide basic information, background, and an overview on one more more aspects of your topic, written by a recognized authority on the topic.
Articles in scholarly encyclopedias also usually include bibliographies, highlighting some of the most important books and journal articles written on that topic to date.
A few of our reference titles relating specifically to Earth's polar regions are listed here. We have many more that more broadly cover areas of study including physical environment, climate, terrestrial and marine ecosystems, natural resources and development, exploration, governance, and indigenous peoples. Ask a librarian!