J.P. DOWDS (1961)
Mathematical probability is an
oil-search tool. *World Oil* 153, 99-106.

A.M.M. ELFEKI (1996)
*Stochastic characterization of geological heterogeneity and its
impact on groundwater contaminant transport.*
Ph.D. thesis, Delft University of Technology,
Balkema publishers, The Netherlands, 301p.

A.M.M. ELFEKI, AND F.M. DEKKING (2000)
A Markov chain model for subsurface characterization: theory and
applications ,
to appear in *Mathematical Geology.*

R.F. GALBRAITH AND D. WALLEY (1976)
On a two-dimensional binary process:
*Journal of Applied Probability* 13, 548-557.

D.K. PICKARD (1980)
Unilateral Markov fields:
*Advances in Applied Probability* 12, 655-671.