TY  - JOUR
AU  - Peter R. Hartley and Kenneth B. Medlock III
PY  - 2013/04//
TI  - Changes in the Operational Efficiency of National Oil Companies
JO  - The Energy Journal
VL  - Volume 34
DO  - 10.5547/01956574.34.2.2
IS  - 2
KW  - National Oil Company
KW  - Government ownership
KW  - Revenue efficiency
KW  - Data envelopment
KW  - Stochastic Frontier
SN  - 1944-9089
UR  - http://www.iaee.org/en/publications/ejarticle.aspx?id=2514