Hard copy, bound encyclopedias are out of date, why would teachers force students to even reference them? People of the baby boomer generation still accept the flaws in the information provided in these dated reference tools. I no longer can recommend this. Students today don't even look at an encyclopedia as the authority, this concept is unknown to them.
This leads to the use of crowd sourced references, such as Wikipedia.com; which, when I was in college was not seen as a credible source. At one time we could know enough general information about a subject to be considered well rounded, that is to say, if we knew the encyclopedia definition of the given subject. However today, the depth of knowledge on one particular subject is entirely more specialized. If I want to know how to build a canoe, the encyclopedia can only tell me, it comes from a tree, a native American used to sit there for days or weeks at a time with a crude tool to hollow it out, and then he had a canoe.
Today, an individual specialized website will tell me the exact steps and tools needed to accomplish this goal; maybe even give you the labor intensive traditional route, and a modern way of doing it. Entire groups of people get together to discuss the topic, the wealth of information so completely exceeds comprehension, our brains cannot absorb it, so we (as the kids learned it seems at birth) put on the blinders.