It doesn't need to be Britannica specifically, just any encyclopedia that isn't subject to the demands of the present. Wikipedia is modified constantly because

It doesn't need to be Britannica specifically, just any encyclopedia that isn't subject to the demands of the present. Wikipedia is modified constantly because it's politically relevant on a day-to-day basis. Older books aren't necessarily always more objective, but they tend to have different viewpoints – and being made of paper, the text can't be changed when politically expedient. So if possible, I always recommend people read as wide a selection of information as possible, and maybe my initial suggestion of a specific paper encyclopedia was not actually the best one, and a varied selection of different ones from different eras would actually be better. My basic point is just that Wikipedia is very biased on certain topics and thus treating it as a sacred, complete repository of knowledge to read is not a good idea.