Nuttakorn Intaravicha. (2020) Efficacy of Shoebox Spectrophotometer Program Working on Smartphone to Measure Absorbance for Soil Phosphorus Analysis by Molybdenum Blue Colorimetric Method. <i>Thai Agricultural Research Journal</i>, <i>38</i>(2), 150-160.Nuttakorn Intaravicha. "Efficacy of Shoebox Spectrophotometer Program Working on Smartphone to Measure Absorbance for Soil Phosphorus Analysis by Molybdenum Blue Colorimetric Method". Thai Agricultural Research Journal 38 (2020):150-160.Nuttakorn Intaravicha. Efficacy of Shoebox Spectrophotometer Program Working on Smartphone to Measure Absorbance for Soil Phosphorus Analysis by Molybdenum Blue Colorimetric Method. Department of Agriculture:ม.ป.ท. 2020.