* A manual for the preparers and users of eco-efficiency indicators (UNCTAD/ITE/IPC/2003/7), Nº de venta: E.04.II.D.13, 1º de febrero de 2004
A manual for the preparers and users of eco-efficiency indicators (UNCTAD/ITE/IPC/2003/7), Sales no. E.04.II.D.13, 1 February 2004