Changes in World Corn Shipping Pattern under the Background of COVID-19 Pandemic and Russia-Ukraine Conflict
ZHAO Pengjun, YIN Zhaoyou, ZHANG Mengzhu, NIU Yingnan, HE Zhangyuan
Acta Scientiarum Naturalium Universitatis Pekinensis . 2024, (6): 1094 -1106 .  DOI: 10.13209/j.0479-8023.2024.023