3Leuchovius,T. , E.J. Stevens, D. S. Fraser, et al. Bakkegard. Plot machine modules: More flexibility and lower costs. The Flexiseeder Approach [ J ]. Proceedings of IAMFE Congress 2008, AgroTech, Arhus, Denmark,2008,60: 115- 120.
4Thian, L.P., E.J. Stevens, T. Leuchovius, et al. Flexi Technical Note - 002. [ J]. Proceedings of IAMFE Denmark 2008. AgroTech, Arhus, Denmark.. 2008,6:123 - 125.
5Stevens E. J. , T. Leuchovius, T. Gaardlos,et al. Gray. Flexiseeder cell wheel and distributor module:An overview including technical specifications [ J ]. Flexi Technical Note - 005. Proceedings of IAMFE Denmark 2008. AgroTech, Arhus.Denmark,2008,6 : 126 - 130.
6Small, G. T. , N.B. Baker, E.J. Stevens, et al. Bakkegard. Flexiseeder air assisted delivery and distribution module. An overview including technical specifications. Flexi Technical [ J]. Note - 003. Proceedings of IAMFE Denmark 2008. AgroTech. A rhus, Denmark,2008(6) :131 - 135.
7Stevens, E.J. , T. Leuchovius, T. Gaardlos, et al. 2008. Flexiseeder seed and fertilizer coulter module: An overview including technical specifications. Flexi [ J ]. Technical Note - 004. Proceedings of IAMFE Denmark 2008, AgroTech, Arhus, Denmark. 2008,6 : 140 - 145.