A Lot of 5 Encyclopedia books titled "The New Encyclopaedia Britannica in 30 Volumes". These are "Macropaedias" providing in-depth knowledge.
Volume 11: Livingstone - Metalwork
Volume 12: Metamorphic - New Jersey
Volume 13: Newman - Peisistratus
Volume 14: Peking - Probability
Volume 15: Proboscidea - Rubber
These hardcover books were published in 1974 by William Benton; Encyclopaedia Britannica Inc. and were printed in the United States.
They come in good pre-owned condition with no writing in the books. The cover of Volume 11 has some creases.