I am including a sonnet redouble' (heroic crown of sonnets) as the last piece in my first volume of poetry. I am trying to find the format for classical-era sonnets redouble's. I have searched and searched, and all I am finding are works from the last few decades. I have to think there just has to be something older, ideally, classical extant sonnets redouble's. I appreciate that none exist from the era from which they originated circa the 13th century.
Many, many thanks for any inights/pointers.