For public domain text not available online, you could use academic referencing style e.g Harvard style "Jess (2021) My Public licence poems"
Arali zwo ṅwalwaho zwa fhethu ha tshitshavha tshoṱhe zwi si ho onḽaini, ni nga shumisa tshitaela tsha academic reference. Sa tsumbo, Harvard style "Jess (2021) My Public licence poems"