Distribution and current infection status of Biomphalaria straminea in Hong Kong oleh Xin Zeng, Wing Chung Yiu, Kwan Ho Cheung, Ho Yin Yip, Wenyan Nong, Ping He, Dongjuan Yuan, David Rollinson, Jian-Wen Qiu, Ming Chiu Fung, Zhongdao Wu, Jerome Ho Lam Hui