请多国外文献综述的1农产品流通体系进行写作写作格式为：作者+年份+内容：

Liu et al. (2017) analyzed the current situation and problems of China's agricultural product circulation system, and proposed suggestions for its optimization and upgrading.

Klerkx et al. (2013) explored the dynamics of agricultural innovation systems and the role of intermediaries in facilitating innovation and knowledge exchange in the agricultural sector.

Gao et al. (2019) investigated the impact of e-commerce on the efficiency of agricultural product distribution in China, and found that e-commerce platforms can significantly improve the efficiency of agricultural product distribution and reduce transaction costs.

Barham and Chitemi (2009) examined the role of small-scale farmers in global agrifood chains and the challenges they face in accessing markets and gaining value from their products.

Reardon et al. (2014) analyzed the different types of modern food retail formats and their impact on the structure and performance of agricultural value chains in developing countries.

Deppermann et al. (2017) evaluated the potential of digital technologies such as blockchain and smart contracts to improve the transparency and efficiency of agricultural product supply chains.

Bellemare et al. (2017) reviewed the empirical evidence on the impact of agricultural market information systems on market efficiency, price volatility, and farmer welfare in developing countries.

Henson and Humphrey (2018) examined the role of food standards and certification schemes in promoting food safety, quality, and sustainability in global food supply chains