You tried going to https://circle.ubc.ca/bitstream/2429/589/2/Richer_White_Dwarf_Stars_UBC_Dept_Physics_Astronomy_Colloquium_2008.mp3, and it doesn't exist. All is not lost! You can search for what you're looking for.
https://circle.ubc.ca/bitstream/2429/589/2/Richer_White_Dwarf_Stars_UBC_Dept_Physics_Astronomy_Colloquium_2008.mp3