Subject
- Congresses and conventions11
- Mexico11
- Women scientists11
- Women chemists10
- Petroleum industry and trade9
- Women in chemistry9
- Women physicists9
- Pasteur, Louis, 1822-18958
- Postcards8
- Women in physics8
- Chemistry7
- Nuclear energy7
- American Chemical Society6
- Germany (East)6
- Petroleum industry and trade--Government ownership6
- Petróleos Mexicanos6
- Semipostal stamps6
- Soviet Union6
- Special relativity (Physics)6
- Benzene5