1. Alén R, Hartus T (1988) UV spectrophotometric determination of lignin from alkaline pulping liquors. Cellul Chem Technol 22: 613–618
2. Bagby MO, Cunningham RL, Maloney RL (1973) Ultraviolet spectral determination of lignin. Tappi 56 (4): 162–163
3. Bagby MO, Nelson GH, Helman EG, Clark TF (1971) Determination of lignin in non-wood plant fiber sources. Tappi 54: 1876–1878
4. Barnes CA, Collias EE, Felicetta VF, Goldschmid O, Hrutfiord BF, Livingston A, McCarthy JL, Toombs GL, Waldichuk M, Westley R (1963) A standardized Pearl-Benson, or nitroso, method recommended for the examination of spent sulfite liquor or sulfite waste liquor concentration in waters. Tappi 46: 347–351
5. Bartunek R (1959) A nonhydrolytic spectrophotometric method for determining lignin in high-purity pulps. Tappi 42: 553–556