[XeTeX] Replacing `` and '' with the unicode equivalences in BibTeX?

[Atip Asvanund]

Hello all,

I am very much settled in using XeTeX after a few weeks of playing around
and bombarding this list with nonsense questions.

I try to use XeLaTeX with BibTeX. In certain BibTeX styles (e.g., Harvard
Style) bibliography is printed out with quotaions around document
titles.

However, with XeLaTeX they are printed out as `` and '', rather than the
unicode equivalences. Is there a way I can redefine the global property so
that the unicode equivalences will show up properly?

Thank you,

Atip