The term 'Bhugol', referring to the study of the Earth or geography, was first documented and utilized in the ancient Indian astronomical treatise known as the Suryasiddhanta.
While other ancient texts like the Mahabharta, Upnishada, and Puranas discuss various aspects of cosmology and the Earth, the specific term 'Bhugol' is primarily associated with the Suryasiddhanta as its earliest known source.