A visitor looks at books on sale at a booth during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

Specialists attend a forum during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

A staff member (R) introduces books to a visitor at a booth during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

A visitor looks at books on sale at a booth during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

A staff member introduces books to visitors at a booth during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

Visitors and staff of exhibitors discuss business during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

A visitor looks at books on sale at a booth during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)

A visitor reads a book at a booth during the 2018 BookExpo in New York, the United States, May 30, 2018. BookExpo, one of the largest book shows in North America, runs from Wednesday till Friday in New York, attracting about 400 exhibitors across the country and around the world. (Xinhua/Wang Ying)