1. BPS, Luas Panen Sayuran di Indonesia 2010–2014, Badan Pusat Statistik dan Direktorat Jendral Hortikultura [Online], 2014. Retrieved from: http://www.bps.go.id/aboutus.php?tabel=1&id_subyek=55>. Accessed on: 4 May 2015.
2. K. Pelleg, “Biomechanics of fruit and vegetables,” Journal of biomechanics. 1985;18 (11), 843–862.
3. N.N. Mohsenin, Physical Properties of Plant and Animal Materials: Structure, Physical Characteristics, and Mechanical Properties. Gordon and Breach Science Publishers Inc. New York, 1986.
4. M.E. Wright, J.H. Tappan and F.E. Sistler, “The size and shape of typical sweet potatoes,” Transactions of the ASAE, vol. 29, no. 3, pp. 678–0682, 1986.
5. S. Kaleemullah and R. Kailappan, “Geometric and Morphometric Properties of Chillies,” International Journal of Food Properties, vol. 6, no. 3, pp. 481–498, 2003.