Published in 1972 and written around 1970
Yu Guangzhong, born in 1928, came to Taiwan at the age of 21.
He claimed that he wrote "Nostalgia" in only 20 minutes, 20 years after leaving home, so Nostalgia was written in:
1928+21+20=1969
The publication time should be It was the early 1970s
Reference: /z/q135011630.htm?rq=96039088&ri=5&uid=0&ch=w.xg.llyjj