All
main website
http://www.ispd.cc/contests/19/
http://www.pld.ttu.ee/~maksim/benchmarks/iscas89/verilog/
Standard
https://filebox.ece.vt.edu/~mhsiao/iscas89.html
https://davidkebo.com/benchmark
https://github.com/gate-lab/RANE/wiki/Benchmarks
Links are embedded in title Design Automation Algorithms for the NP-Separate VLSI Design Methodology