Authorized Dealers and Financial Institutions

December 29, 2011

Primary Dealers

Cantor Fitzgerald & Co.

Jefferies & Co.

J.P.Morgan Securities, Inc.

Merrill Lynch, Pierce Fenner & Smith

Morgan Stanley & Co.

RBC Capital Markets, LLC

UBS Securities, LLC

Other

BOSC, Inc. (Tulsa)

Country Club Bank (Edmond)

Commerce Bank (Kansas City)

Raymond James & Assoc. (Houston)

Sanders, Morris, Harris (Tulsa)

Southwest Securities (Dallas)

Stifel Nicholas (Dallas)

UMB Bank, NA (Kansas City)

Wells Fargo Securities (Chicago)