citation
Sills, E., Shanley, P., Paumgarten, F., de Beer, J., Pierce, A. 2011. Evolving perspectives on non-timber forest products . Tropical Forestry No.7. In: Shackleton, S, C. Shackleton, P. Shanley (eds.). Non-timber forest products in the global context. :23-51. Heidelberg, Springer-Verlag. ISBN: 978-3-642-17982-2..
