There are different types of encyclopedias. Some are general and have pages on lots of topics. The English language "Encyclopædia Britannica" and German "Brockhaus" are general encyclopedias. Some are about specific topics. For example, there are encyclopedias of medicine or philosophy. Others include the "Dictionary of National Biography", the "Dictionary of American Naval Fighting Ships", and "Black's Law Dictionary". There are also encyclopedias that that cover many topics with one perspective or one cultural bias. They include the "Great Soviet Encyclopedia" and Conservapedia.