For public domain text not available online, you could use academic referencing style e.g Harvard style "Jess (2021) My Public licence poems"
Ngombhalo wesizinda esisesidlangalaleni ongatholakali ku-inthanethi, ungasebenzisa isitayela sereferensi yezemfundo isb isitayela saseHarvard "Jess (2021) Izinkondlo Zami Zelayisensi Yomphakathi"