an Entity references as follows:
The Green Knight (Danish: Den grønne Ridder) is a Danish fairy tale, collected by Svend Grundtvig (1824-1883) in Danish Fairy Tales (18??) and by Evald Tang Kristensen (1843-1929) in Eventyr fra Jylland (1881). Andrew Lang included a translation of Kristensen's version in The Olive Fairy Book (1907).