4Williams J. E-commerce and agricultural commodity mar- kets:E-commerce and the lessons from nineteenth century ex- changes [J]. American Journal of Agricultural Economics, 2001,83 (5) : 1250-1257.
5Carpio C E, Isengildina-Massa O, Lamie R D,et al. Does ecommerce help agricultural markets? The case of MarketMaker [J]. Choices,2013,28(4) :1-6.
6Hobbs J E, Bailey D, Dickinson D L,et al. Traceability in the Canadian red meat sector: Do consumers care? [ J]. Canadian Journal of Agricultural Economics, 2005,53 ( 1 ) : 47-65.
7Lee T L. Using qualitative methods in organizational research [M]. Beverly Hills, CA: Sage, 1999.
8Eisenhardt K M. Better stories and better constructs:The case for rigor and comparative logic [J]. Academy of Mana- gement Review, 1991,16 (3) : 620- 627.
9Eisenhardt K M, Graebner M E. Theory building from cases : Opportunities and challenges [J]. Academy of Mana- gement Journal .2007,50( 1 ) :25-32.
10Eisenhardt K M. Building theories from case study research [ J ]. Academy of Management Review, 1989,14 (4) :532-550.