Allan (1981), Beentje (1990), Bennun (1994b), Bennun et al. (in press), Blackett (1994f), Coe (1967), Coe and Foster (1972), Davies and Vanden Berghe (1994), Fairweather (1993), KIFCON (1992), Kokwaro and Beck (1987), Lockwood (1995), Lubanga (1992), Milner et al. (1993), Rehder et al. (1981), Shah and Upadhyaya (1995), Young and Evans (1993).