Darke, A. (1993). Trees: The fourth state of water ; Andrew Darke & Andy Goldsworthy.
Cita Chicago (17th ed.)Darke, Andrew. Trees: The Fourth State of Water ; Andrew Darke & Andy Goldsworthy. o.O, 1993.
Cita MLA (8th ed.)Darke, Andrew. Trees: The Fourth State of Water ; Andrew Darke & Andy Goldsworthy. 1993.
Atenció: Aquestes cites poden no estar 100% correctes.