1. Extraction of ions from a flame
2. Seventh Symposium (International) on Combustion;Deckers,1959
3. Seventh Symposium (International) on Combustion;Knewstubb,1959
4. Eighth Symposium (International) on Combastion;De Jaegers,1962
5. Ninth Symposium (International) on Combustion;Green,1963