Look for text where the copyright no longer applies - for example most books that were published before 1920
ⵙⵙⵉⴳⵍ ⴰⴹⵕⵉⵚ ⵏⵏⴰ ⵙⵓⵍ ⵓⵔ ⵉⵍⵉⵏ ⵉⵣⵔⴼⴰⵏ ⵏ ⵓⵎⴳⴰⵢ - ⵙ ⵓⵎⴷⵢⴰ, ⴰⵎⴰⵜⴰ ⵏ ⵉⴷⵍⵉⵙⵏ ⵏⵏⴰ ⵜⵜⵓⵥⵕⴰⴳⵏⵉⵏ ⴷⴰⵜ 1920