At the 1934 EMS St Andrews Colloquium

At the 1938 EMS St Andrews Colloquium

At the 1951 EMS St Andrews Colloquium

At the 1955 EMS St Andrews Colloquium

At the 1959 EMS St Andrews Colloquium

At the 1964 EMS St Andrews Colloquium

At the 1968 EMS St Andrews Colloquium