1. A computer-implemented method for exploring external data sources, the method comprising: selecting a first function from a function library in a spreadsheet application based on a first user input; designating a first data source for the first function based on a second user input, wherein the first data source comprises a first dataset stored externally to the spreadsheet application; arranging a first cell formula comprising the first function and a first identifier for the first data source in a first cell of a spreadsheet; selecting an output function from the function library based on a third user input; designating a source function's reference based on a fourth user input, wherein the source function's reference indicates the first cell of the spreadsheet; designating an output location in a spreadsheet of the spreadsheet application based on a fifth user input; arranging a second cell formula comprising the selected output function, the designated source function's reference, and the designated output location in a second cell of the spreadsheet; translating the first cell formula in the first cell indicated as the source function to the output function into a data query for a data engine in response to a refresh action; and sending the data query to the data engine, wherein the data engine is configured to execute the data query against the first dataset.