On or in the document ?

0Hi,02br
00could you help me and let me know what is correct English and why:02br
00"an amount stated on an invoice" or "an amount stated in an invoice"02br
00"a statement on a Bill of Lading" or "a statement in a Bill of Lading"02br
00"a wrong figure on a Proforma Invoice" or "a wrong figure in a Proforma Invoice"02br
00"a note on a piece of paper" or "a note in a piece of paper"02br
00I believe to have learned "a statement on a document", but some native speakers from Canada say it must be "a statement in a document" even if it is just one sheet of paper, and not a document in the sense of a book or dossier.02br
00Thanks in advance for your help.02br
00Best regards, Burkhard0-