| ucdavis.edu | Long-Term Research on Agricultural Systems |
| sustainweb.org | Sustain: the Alliance for better food and farming |
| stedula.be | Sustainable Agriculture, Policy Research Centre for - Steunpunt Duurzame Landbou |
| seedballs.com | Seed Balls |
| ofrf.org | Organic Farming Research Foundation |
| landstewardshipproject.org | Land Stewardship Project |
| ac.th | Regional Information Service Centre for Southeast Asia on Appropriate Technology |
| roadsideamericainc.com | Roadside America, Inc. |
| kutztown.edu | Pennsylvania German Cultural Heritage Center at Kutztown University |
| kemptontrain.com | WK&S Railroad Line |
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