Google Workbook as a Workflow Variable

Hi there. I’m attempting to pass a Google workbook as a variable to another workflow but I’m unsure what the best option do do so would be. Can I pass the workbook as an agrument to the called workflow, or is it better to pass the sheet name as an argument and re-open the Google workbook? If it’s the first option, what data type should the argument be, and would I then have to re-use the 'Use Google Spreadsheet scope"?