Hello Liz,
I think to get the Birth Cert for Bernard first to see what his Mother's maiden name is,
then if her maiden name is the same as on the Marriage you have found,
then to get the Marriage Cert.
which will give you the names of their parents,
from my experience the Death Cert only has the, Date, Place and Name, cause of Death, and the Informant, not much more added information on it,
Averil