Lewis, Bob (June 14, 2008). "Warner takes self out of VP mix". The San Francisco Chronicle. Associated Press. Diarkibkan daripada yang asal pada June 18, 2008. Dicapai pada June 15, 2008.
Lewis, Bob (June 14, 2008). "Warner takes self out of VP mix". The San Francisco Chronicle. Associated Press. Diarkibkan daripada yang asal pada June 18, 2008. Dicapai pada June 15, 2008.