The thinnest book in the UK is "The British Cookbook", the thinnest book in France is "The Biography of French Celebrities", the thinnest book in the United States is "American History", and the thinnest book in Italy is "The Heroic Epic of Italy" and "The Record of the Italian Army", the thinnest book in Germany is "The Powerful German Navy" and the thinnest book in China is "The Chinese Who Won the Nobel Prize".

There are also unconfirmed rumors: the smallest book in the world was found in Zhengzhou, Henan, my country. According to Guinness Headquarters in Shanghai, the Islamic holy book "Quran" collected by a retired worker surnamed Bai in the city is 25.708 mm long, 19.517 mm wide, 9.620 mm thick, and weighs 4.318 grams.

It is nearly 5 grams lighter than what was said to be the "world's smallest rare copy of the Koran" discovered in Algeria in 1988. The book was printed about 200 years ago and has 30 volumes and 114 chapters. The pages are as thin as cicada wings and edged with gold.