Is The Loremaster Achievement Doable?

Lore is only available in three mission types and doesn't appear every time, or am I just missing where it spawns?

Does anyone have this achievement? 0.0% on Steam. I have over seventy hours in game and have ... 7 ... lore. I can't tell how many lore entries there are to get but it is at least mid twenty. I haven't see any tips online for how to get it.

Does anyone have it?

Are the codex contents online somewhere that I could read them and give up on the achievement?