Rocketry 2021: commercial space surges into the lead. Bob Zimmerman BehindtheBlack.com.

Photo:  Diagram of multi-staged rocket by Johann Schmidlap.  Conrad Haas.
was an influence of Schmidlap, but Schmidlap was the first to publish multistage rocket designs in print. 

https://behindtheblack.com/behind-the-black/essays-and-commentaries/2021-the-year-that-private-enterprise-took-over-rocketry/