: Authority sites like eLife provide data-heavy papers on long-term trends in adult development, such as historical changes in human height.
If you are actually looking to a long paper (essay or research project) related to mature themes or individuals: maturebabe
Could you clarify if you are looking for to buy or help drafting an essay on a specific topic? You're Old Babe Card - Hitchcock Paper Co. : Authority sites like eLife provide data-heavy papers