Mark Mazzetti e Katie Benner, Trump Pressed Australian Leader to Help Barr Investigate Mueller Inquiry's Origins, in The New York Times, 30 settembre 2019, ISSN 0362-4331 (WC · ACNP). URL consultato il 3 novembre 2019 (archiviato dall'url originale il 30 settembre 2019).
«Like the call with the Ukrainian president, Volodymyr Zelensky, the discussion with Mr. Morrison shows the president using high-level diplomacy to advance his personal political interests.»