In the text that I am reading now, the Greek word μονάδαι is used to indicate "units". I have understood it as a plural form of μονάς, however, I could only find μονᾰ́δε in the dual form and μονᾰ́δες in the plural form in the dictionary(Attic). Is the word μονάδαι another dialect of μονᾰ́δες? Or is it just mistaken in the text? Or is μονάδαι a form of another word than μονάς? Thank you!