1 Subjects: “...environmental certification...”

2 Subjects: “...third-party certification...”

3 Subjects: “...eco-certification...”

4 “.... It also gives a comprehensive history of the use and chemical content of guano and certification schemes...”

5 “..., certification schemes, international law and commodity markets. In doing so, the contributions contrast existing...”

6 “... smallholder farmers with low-cost certificates for land held under customary tenure. Yet there are many...”