We start with the joint MGF of , which is (see [46],
p. 68, eq. B18)

(7.8) 
for
,
,
... ,
.
We can rewrite (7.8) as
where
Alternatively,
where
Define the by matrix
and
.
Then,
where
is an by1
column vector of ones.
Thus,
is the reciprocal
of the product of the elements of
,
denoted by
where
is the product of the
elements of the argument.
Baggenstoss
20170519