Peirce proposes several typologies and definitions of the signs. Rajputs adhered to architectural texts that categorized different typologies of fortifications based on their geography. Political scientists have created many typologies describing variations of authoritarian forms of government. This appeared applicable in particular to recognizable urban typologies. There is a multitude of definitions of a learning organization as well as their typologies. Researchers have developed models for understanding an organization's culture or developed typologies of organizational culture. Several other typologies and types of loneliness exist. As a result, a number of typologies of group change theories have been proposed. There are many different typologies of revolutions in social science and literature. Different typologies of political culture have been proposed. There are two primary typologies of infant vocalizations. In the 19th century, two hybrid building typologies evolved in Singapore. This criticism introduces important questions for attachment typologies and the mechanisms behind apparent types. There are more than fifteen mixed method design typologies that have been identified. Such post-war regimes are excluded from political science typologies of fascism however.