gives notice of the sale to the owner of record at the time of the sale and any person with a substantial property interest of public record in the tract or item of real property.
at the last address of the owner for the property, as indicated in the records of the county auditor; and
However, if the address of the person with a substantial property interest of public record is not indicated in the public record that created the interest and cannot be located by ordinary means by the person required to give the notice under subsection (a), (b), or (c), the person may give notice by publication in accordance with IC 5-3-1-4 once each week for three (3) consecutive weeks.
the certificate of sale reverts to the county executive and may be retained by the county executive or sold under IC 6-1.1-24-6.1.
IC 6-1.1-25-4.5