What are Three types of informational references

The three types of "informational references" are "Atlas, Almanac and Encyclopedia".

Atlas is a collection of map. Traditionally atlas was in a form of book contain maps of the whole world. Nowadays it is available in multimedia format which provides interactive information.

Almanac is an "annual publication" which contains event of the forthcoming year. This includes "weather forecasts", "tide tables", "farmers' planning date", etc.

Encyclopedia contains information about various subjects. This is the one source solution for the need of information.