@misc{1159401,
  author = {Sam A Margolis},
  title = {Reference materials for organic nutrient measurement:},
  year = {1982},
  month = {1982-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.SP.635},
  language = {en},
}