Douglas Adams (2016). “Dirk Gently's Holistic Detective Agency Box Set: Dirk Gently's Holistic Detective Agency and The Long Dark Tea-Time of the Soul”, p.410, Simon and Schuster
Douglas Adams (2016). “Dirk Gently's Holistic Detective Agency Box Set: Dirk Gently's Holistic Detective Agency and The Long Dark Tea-Time of the Soul”, p.209, Simon and Schuster