4. External examiner for the PhD viva of Mr. Alexander Shukhobodskiy on 14 November 2018, University of Sheffield, UK.

3. External examiner for the PhD viva of Ms. Natasha Jeffrey on 28 May 2014, University of Glasgow, UK.

2. External examiner for the PhD viva of Mr. David Kurdize on 20 January 2014, Queen's University Belfast, Northen Ireland, UK.

1. External examiner for the PhD viva of Mr. Khalil Al-Ghafri on 21 December 2012, University of Sheffield, UK.