With the sale agreement, closing statement, lawyer's trust records, corporate financial statements and tax filings, personal tax records, and a continuous bank trail from the sale proceeds through every account to the investment.
Every account the money touched needs a statement
Hypothetical example: the bakery sale proceeds went to a corporate account, then partly to a term deposit, then to a joint personal account, and a portion came from a parent as a gift. That is four separate threads and each one needs its own paper. For the sale: the agreement, the closing statement and the accountant's records of how the price was determined.
For the corporation: financial statements and tax filings covering the years that built the value. For the personal accounts: statements covering every transfer with the amounts matching. For the gift: a gift letter, evidence of the parent's own lawful source of those funds and the transfer record.
Currency conversion adds another document. Assemble this before subscribing to anything, because gaps discovered later can take many months to close and some cannot be closed at all.