HONG KONG -- Five books in traditional Chinese characters -- an outline for the study of Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era and four books on President Xi's local work experience -- debuted Wednesday at the Hong Kong Book Fair.

The books were published and distributed by two publishers under the Sino United Publishing (Holdings) Ltd.

The five books serve as an important reference for various social sectors in Hong Kong and Macao to develop the economies, improve people's well-being, enhance patriotism and the sense of national identity, and advance the successful practice of "one country, two systems."

Senior officials from the central authorities and the Hong Kong Special Administrative Region government as well as representatives from the publishing sector attended the launching ceremony.