A publishing house in north China's Inner Mongolia Autonomous Region has published an encyclopedia in the Mongolian language on folk customs of the Mongolian ethnic group.

The six-million word encyclopedia includes 20,000 entries in four volumes, covering economic development, traditional culture, science and technology and people's life, and derivation of family names.

Editors of the Scientific and Technological Publishing House of Inner Mongolia initiated the project 12 years ago. To collect sufficient and accurate historical material for the book, they carried out series of research studies and surveys in and out of China, gaining over ten million words of rare historical data about Mongolian folk customs.

The book will be a valuable document and a record of domestic and international study on the Mongolian people, folklore, history, linguistics, said an editor.

The book will soon be published in Chinese and English, he said.