I'd also recommend book that's developed the ideas of the Permaculture further to suit better for farming: https://www.regenerativeagriculture.co/ Just bought the book and it's a very thorough and practical guide on how to run small farm profitabily while building new soil and implementing Permaculture patterns. Richard Perkings who has written the book is a pioneer in regenerative agriculture and runs his own farm at Sweden (https://youtu.be/J_htLIUKX1Y) He explains the principles and theories behind his farm in this great lecture he kept at food-related hackaton: https://youtu.be/3Knn7ZH4Tiw