Where does this definition of 人口的年龄结构类型 come from?
This entry for 人口的年龄结构类型 is sourced from Main Dictionary, one of the dictionaries and corpora merged into Lughet.
What is Lughet?
Lughet is a free trilingual dictionary covering nearly five million entries across Uyghur, Chinese, and English, drawn from more than ten source dictionaries and corpora.