Curated OER
Grafting
Compatible plants can be grafted together. Some of the reasons for doing so are explored in this PowerPoint. Actual techniques for the process are not explored completely, but the slides give a lot of information and are nicely presented.
OpenStax
Open Stax: Growing Pains of Urbanization: Relief From the Chaos of Urban Life
Learn how different economic classes in urban centers spent their leisure time in the late 19th century. Includes a good discussion of machine politics and the role it played in the lives of the lower classes, as well as its negative...