De Agricultura
Philo Judaeus
The works of Philo Judaeus, the contemporary of Josephus, volume 1. Yonge, C. D., translator. London: Henry G. Bohn, 1854.
And if there be any tree belonging to what is called the wild class, which does not bear eatable fruit, but which is able to be a fence to and a protector of that which is eatable, that also I will manage, not for its own sake, but because it is calculated by nature to be of use to what is necessary and very useful.