  In this paper, we propose a theoretical scheme of ghost imaging in terms of
$N$th-order correlated thermal light. We obtain the Gaussian thin lens
equations in the ghost imaging protocol. We show that it is possible to produce
$N-1$ ghost images of an object at different places in a nonlocal fashion by
means of a higher-order correlated imaging process with an $N$th-order
correlated thermal source and correlation measurement. We investigate the
visibility of the ghost images in the scheme, and obtain the upper bounds of
the visibility for the $N$th-order correlated thermal-light ghost imaging. It
is found that the visibility of the ghost images can be dramatically enhanced
when the order of correlation becomes larger.
