Weaveworld

Both 1987 editions are first editions in their territories. Precedence between them is not firmly established: some sources date the US Poseidon issue (early October 1987) slightly ahead of the UK Collins issue (mid-October 1987), so the record's flat claim that Collins is the true first overstates the evidence. Treat them as effectively simultaneous 1987 firsts, with the US possibly first to market.