Robert-Tissot, Sarah (2011). "TANTALUM". Royal Australian Chemical Institute. Archived from the original on February 26, 2017. Retrieved March 3, 2019.
Padilla, Abraham (February 2019). "TANTALUM"(PDF). United states geological survey. Archived from the original(PDF) on March 6, 2019. Retrieved March 3, 2019.
Robert-Tissot, Sarah (2011). "TANTALUM". Royal Australian Chemical Institute. Archived from the original on February 26, 2017. Retrieved March 3, 2019.
Padilla, Abraham (February 2019). "TANTALUM"(PDF). United states geological survey. Archived from the original(PDF) on March 6, 2019. Retrieved March 3, 2019.