The list of competitors in IOI’1998 is on the page International Olympiad in Informatics. Results of IOI 1998.
(Snapshot: http://archive.ph/wip/gWQYL. Archive link: https://web.archive.org/web/20180731042606/http://ioinformatics.org/locations/ioi98/results.shtml)
The list of competitors in IOI contests from Ukraine is available on the page International Olympiad in Informatics (Ukrainian)
The bronze medalist certificate follows: