Ashworth, S., & Whealy, K. (2002). Seed to seed: Seed saving and growing techniques for vegetable gardeners (2nd ed.). Seed Savers Exchange.
Cita Chicago Style (17a ed.)Ashworth, Suzanne, y Kent Whealy. Seed to Seed: Seed Saving and Growing Techniques for Vegetable Gardeners. 2nd ed. Decorah, Iowa: Seed Savers Exchange, 2002.
Cita MLA (8a ed.)Ashworth, Suzanne, y Kent Whealy. Seed to Seed: Seed Saving and Growing Techniques for Vegetable Gardeners. 2nd ed. Seed Savers Exchange, 2002.
Precaución: Estas citas no son 100% exactas.