Ball RA, Parecll LC, Vories ED (2001) Short season soybean yield compensation in response to population and water regime. Crop Science 40: 1070-1078.
Board JE, Harville G, Saxton AM (1990) Narrow-row seed yield enhancement indeterminate soybean. Agrononomy Journal 82: 64-68
Board JE, Harville BG (1994) A criterion for acceptance of narrow-row culture in soybean. Agronomy Journal 86: 1103-1106
Boquet DJ (1990) Plant population density and row- spacing effect on soybean at post optimal planting dates. Agronomy Journal 82: 59-64.
Bowers GR, Rabb JL, Ashlock LO, Santini JB (2000) Row spacing in the early soybean production system. Agronomy Journal 93: 524-531.
Buehring NW, Blaine A, Harrison MP, Dobbs RR (2003) Soybean response to selected row spacing and low seeding rates. Mississippi Agriculture and Forestry Experimental Station Information Bulletin 398: 107-113.
Bullock D, Khan S, Raburn A (1998) Soybean yield response to narrow rows is largely due to enhanced early growth. Crop Science 38: 1011-1016.
Cober ER, Voldeng HD (2000) Developing high protein, high yield soybean populations and lines. Crop Science 70: 39-42.
Cordonnier MG, Johnston TJ, (1983) Effects of wastewater irrigation and plant row spacing on soybean yield and development, Agronomy Journal 75: 153-156.
Costa JA, Opliner ES, Pendleton JW (1980) Response of soybean cultivars to planting patterns. Agronomy Journal 72: 153-156.
Ethredge WG, Ashley DA, Woodruff GM (1989) Row spacing and plant population effects on yield components of soybean. Agronomy Journal 81: 417-422.
Fernanado H, Andrade P, Alferedo C, Pablo B (2003) Yield responses to narrow rows depend on increased radiation interception. Agronomy Journal 94: 975-980.
Gan Y, Stulen H, Keulen H, Ckuiper PJ (2002) Physiological response of soybean genotypes to plant density. Field Crops Research 74: 231-241.
Hinson W, Hanson D (1962) Competition studies in soybean. Crop Science 2: 117-123.
Holshouser DL, Wittaker JP (2002) Plant population and row spacing effects on early soybean production systems in the Mid- Atlantic USA. Agronomy Journal 94: 603-611.
Jason KN, Emerson RS (2005) Effect of row spacing and soybean genotype on main stem and branch yield. Agronomy Journal 97: 919-923.
Kasiri H, Kasiri M, Zeinali A, Bagheri M (2006) The effect of row distance and plant density on yield and yield components of three soybean cultivars at summer cultivation. Iranian Journal of Natural Resource and Agricultural Science. Specific Letter of Agronomy and Plant Breeding 13: 147-156. [In Persian with English Abstract].
Khademhamzeh, HR, Karimi M, Rezaie A, Ahmadi A (2004) Effect of planting density and planting date on agronomic traits, grain yield and yield components of soybean. Iranian Journal of Agricultural Science 35(2): 357-367. [In Persian with English Abstract].
Khajuienejad Gh, Kazemi H, Alyari H, Javanshir A, Arvin M (2004) Effects of irrigation levels and plant density on growth and yield of soybean cultivars in second cropping. Scientific Journal of Agriculture 1(6): 67-88. [In Persian with English Abstract].
Kilen TC (1990) Brachytic stem and narrow leaflet effects on soybean seed composition and yield. Crop Science 30: 1006-1008
Kouchaki A, Kabiri K, Farzaneh J (1991) Yield of soybean cultivars at Mashhad condition. Journal of Science and Industrial Agriculture 5(1): 91-100. [In Persian with English Abstract].
Latifi N (1993) Soybean cultivation (physiology and agronomy). Iranian Academic Center for Education, Culture and Research Branch of Mashhad. 282 pp. [In Persian].
Sharikian MA, Babaian N (2000) Effect of plant population on yield, yield components and grain quality of soybean cultivars. Iranian Journal of Natural Resource and Agriculture 7(1): 3-12. [In Persian with English Abstract].
Stefan S, Craig EA, Michael HD (2004) Forage soybean yield and quality responses to plant density and row distance. Agronomy Journal 96: 966-970.
Vasilia A, Fasoula M, Roger B (2004) Divergent selected at ultra low plant density for seed protein and oil content within soybean. Field Crop Research 78: 256-264.
Weaver DB, Akridge RL, Thomas CA (1991) Growth habit, planting date and row spacing effects on late planted soybean. Crop Science 31: 305-810.
Zarrinzadeh J (1993) Comparison of yield and yield components in three soybean cultivars in second croppnig at Mashhad condition. M.Sc. Thesis in Agronomy, Ferdowsi University of Mashhad. 96 pp. [In Persian with English Abstract].