The purchase agreement, the American company's share register or membership ledger after closing, incorporation documents for both entities, and any holding-company records that sit between them.
Follow the ownership line without narration
Hypothetical example: the Alberta corporation bought the American carrier's shares, but the deal was structured through a newly created holding company and a portion was left with the vendor for two years. That is a legitimate structure and it needs to be shown, not summarised. Provide incorporation documents for every entity in the chain, the register showing who holds what after closing, the purchase agreement including any vendor-retained interest, and the shareholders' agreement if one governs control.
Then show both companies operating: leases, insurance certificates, customer contracts, payroll registers, equipment lists. The relationship must exist when the petition is filed, so if any step is pending, complete it first. A structure described as being finalised is not evidence of a present relationship.