1. Hon DNS, Minemura N (1991) Color and discoloration. In: Hon DNS, Shiraish N (eds) Wood and cellulosic chemistry. Marcel Dekker, New York, pp 395–454
2. Abe Z, Oda K, Matsumura J (1994) The color change of sugi (Cryptomeria japonica D. Don) heartwood from reddish brown-to black. I. The color changes and its causes (in Japanese). Mokuzai Gakkaishi 40:1119–1125
3. Abe Z, Oda K (1994) The color change of sugi (Cryptomeria japonica D. Don) heartwood from reddish brown to black. II. Identification of potassium hydrogen carbonate as one of the causative materials (in Japanese). Mokuzai Gakkaishi 40:1126–1130
4. Takahashi K (1996) Relationships between the blacking phenomenon and norlignans of sugi (Cryptomeria japonica D. Don) heartwood. I. A case of partially black heartwood (in Japanese). Mokuzai Gakkaishi 42:998–1005
5. Takahashi K (1998) Relationships between the blacking phenomenon and norlignans of sugi (Cryptomeria japonica D. Don) heartwood. II. On blacking heartwood containing two main norlignans, sugiresinal and hydroxysugiresinol (in Japanese). Mokuzai Gakkaishi 44:125–133