Chuyo wŏnyenong sanmul kyŏngyŏng silt'ae punsŏk mit saengsanbi chŏlgam pangan = A study on the cost reduction and management analysis of the major horticultural crops
Noksaek sŏngjang e taeŭng han chungjanggi sallim chŏngch'aek ch'ujin chŏllyak. 1/2-ch'a yŏndo = A study on long-term forest management strategies for green growth