@book{ international2013iaea, title={Training Guidelines in Non-Destructive Testing Techniques: Manual for Visual Testing at Level 2}, series={Training Course Series}, number={54}, year={2013}, url={http://www.dgdingfa.net/publications/8614/training-guidelines-in-non-destructive-testing-techniques-manual-for-visual-testing-at-level-2}, publisher={INTERNATIONAL ATOMIC ENERGY AGENCY}, address={Vienna} }