Antzeko izenburuak: The World Book Encyclopedia :
Gaia: Encyclopedias and dictionaries.
- The New Encyclopdia Britannica vol. 19 : excretion geometry /
- The New Encyclopdia Britannica vol. 15 : birds chemical /
- The New Encyclopdia Britannica vol. 17 : decorative edison /
- The New Encyclopdia Britannica vol. 24 : metaphysics Norway /
- The New Encyclopdia Britannica vol. 26 : pre-columbian sacred /
- The New Encyclopdia Britannica vol. 29 : united zoroastrianism /