The following are several examples of how a subject encyclopedia can aid you when you are beginning your research. Historia general de las cosas de la Nueva Espana by Fray Bernardino de Sahagun. American College of Nurse-Midwifery Division of Accreditation Mary Breckenridge founded the Frontier Nursing Service in 1925. The history of the world is one of constant flux. Contemporary maps will often not be a good guide to events of the past.
Historical atlases can help.
Place names can also be used as clues when researching the history of people - gazetteers offer assistance here. Chronologies will offer overviews of world events occurring across a time span of years. The following is an example of how an historical atlas can answer a question a normal atlas would not. Often, the only way to define these terms is through the use of specialized, or subject dictionaries. You will be working with people who have advanced knowledge of a discipline you are being introduced to.