1. Adler E (1977) Lignin chemistry — past, present, and future. Wood Sci Technol 11: 169–218
2. Adler E, Hernestam S (1955) Estimation of phenolic hydroxyl groups in lignin. I. Periodate oxidation of guaiacol compounds. Acta Chem Scand 9: 319–334
3. Adler E, Hernestam S, Wallden I (1958) Estimation of phenolic hydroxyl groups in lignin. Sven Papperstidn 61: 64–647
4. Aulin-Erdtman G (1954) Spectrographic contributions to lignin chemistry. V. Phenolic groups in spruce lignin. Sven Papperstidn 57: 745–760
5. Björkman A, Person B (1957) Studies on finely divided wood. Part 4. Some reactions of the lignin extracted by neutral solvents from Picea abies. Sven Papperstidn 60: 285–292