Jones, Charles O. (Setembro de 2008). «Vice Presidents and Other Heirs Apparent: The Historical Experience of Experience». Presidential Studies Quarterly. 38 (3). pp. 422–432. JSTOR41219688. doi:10.1111/j.1741-5705.2008.02653.x
Jones, Charles O. (Setembro de 2008). «Vice Presidents and Other Heirs Apparent: The Historical Experience of Experience». Presidential Studies Quarterly. 38 (3). pp. 422–432. JSTOR41219688. doi:10.1111/j.1741-5705.2008.02653.x