UTILITIES AND PIPELINES (Partial Listing)

American Central Gas Companies, Inc.
Brooklyn Union Exp.
Chemetron Corporation
CMS Gas Transmission
Consolidated Natural Gas Company
Consumers Power Company (CMS Subsidiary)
Continental Natural Gas, Inc.
Enogex
Kansas Gas Supply
Lower Colorado River Authority
MCN Investment Corporation
North Texas Gas Co., Inc.
Oklahoma Gas And Electric
ONEOK, Inc.
PG&E Resources Company
Piedmont Gas Gathering Co., Inc.
ScissorTail Energy, LLC
Semco Energy Services
Transok, Inc.
United Cities Gas Company
Willbros Butler Engineers, Inc.
Williams Companies

INDUSTRY CLIENTS (Partial Listing)

Altex Resources
Amerada Hess
Aramco
Atmos Energy Services, Inc.
Bellwood Petroleum Corporation
BP Amoco
Energy Assets International
Chesapeake Energy Corporation
CMS Oil and Gas Company
CMS Gas Transmission
Comstock Resources, Inc.
Dow Chemical Company
EXCO Resources, Inc.
Exxon Company, USA
Ferguson Oil & Gas, Inc.
GE Power Generation
Griggs Oil, Inc.
Helmerich and Payne, Inc.
Kaiser-Francis Oil Company
Kennedy Foundation
Kerr McGee
Lease Management, Inc.
Lower Colorado River Authority
Lumen Energy Corporation
Mannix Oil Company, Inc.
Marathon Oil Company
M.B. Rudman
Merchandise Mart Properties, Inc.
Metropolitan Royalty Corporation
MCV Midland Cogeneration Venture
Mikco, Inc.
Miller Energy Company
Mobil Exploration and Producing U.S., Inc.
Mokeen Limited Partnership
Nadel and Gussman
New Dominion, L.L.C.
NGC Corporation
Nielson & Associates, Inc.
Occidental Petroleum
Oxy USA, Inc.
Panhandle Royalty Company
Petrobras
Petroleum International, Inc.
Petroglyph Energy, Inc.
PetroPeru
Petrostar Energy
Ricks Exploration
River Bend Energy Corporation
Serdrilco, Inc.
Shell Western E&P, Inc.
Sunoco, Inc.
Terra Energy LTD
THUMS
Tinicum Incorporated
Total Petroleum
Whiting Petroleum Corporation
Willbros Engineers, Inc.
Williams Field Services Company
Wintershall AG

ENERGY BANKS AND FINANCIAL GROUPS (Partial Listing)
BA Securities
Bank of America
Bank of California
Bank of Montreal
Bank of New York
Bank of Oklahoma
Bank One
Chase Securities
Citicorp
Commerce Bank
First National Bank of Dallas
First National Bank of Ft. Worth
First United Bank
G.E. Capital Corporation
Heller Financial, Inc.
IMF
International Bank for Reconstruction and Development
International Finance Corporation
MidFirst Bank
NationsBank, N.A.
Northern Trust
The World Bank
Trust Company of the West
U.S. Trust Company
Wells Fargo Bank

FEDERAL, STATE and INTERNATIONAL ORGANIZATIONS (Partial Listing)
Arkansas Riverbed Authority
Australia Commonwealth of Public Prosecutions
Federal Deposit Insurance Commission
InterAmerican Development Bank
International Finance Corporation
Long Beach Development Corporation
Naval Petroleum Reserve
Oklahoma Turnpike Authority
State of California
State of Michigan
State of New York
State of Ohio
State of Oklahoma
State of Texas
State of Pennsylvania
The World Bank
United Nations, New York
U.S. Air Force
U.S. Army Corps of Engineers
U.S Department of Energy
U.S. Navy
U.S. Justice Department

LAW FIRMS (Partial Listing)
Lewis Barnes, P.C.
Ron M. Barnes
Boone, Smith, Davis, Hurst, & Dickman
Brune & Neff Law Office
Conner & Winters
Crowe & Dunlevy
Doerner, Saunders, Daniel & Anderson
Dorwart, Frederic Lawyers

ACCOUNTING FIRMS (Partial Listing)

Deloitte & Touche
Ernst & Young LLP
Michael S. Gray, CPA
KPMG Peat Marwick LLP
PriceWaterhouseCoopers LLP
Sartain Fischbein & Co
Jack E. Short
Tullius Taylor Sartain & Sartain LLP

Complete list of references upon request