Ornprapa Thepsilvisut. (2021) Effect of chicken manure and biochar on growth, pigment concentration and mineral composition in green oak lettuce grown in acid soil. <i>Khon Kaen Agriculture Journal</i>, <i>49</i>(2), 294-303.Ornprapa Thepsilvisut. "Effect of chicken manure and biochar on growth, pigment concentration and mineral composition in green oak lettuce grown in acid soil". Khon Kaen Agriculture Journal 49 (2021):294-303.Ornprapa Thepsilvisut. Effect of chicken manure and biochar on growth, pigment concentration and mineral composition in green oak lettuce grown in acid soil. Faculty of Agriculture:ม.ป.ท. 2021.