In addition to collecting "savings certificates," as the lottery tickets were called, and specimens issued for the three drawings, Chang studied documents issued by the Taiwan Provincial Government and articles in the Central Daily News to get to the bottom of this bit of history.
為了佐證這段幾已湮滅的歷史，張維信除了蒐集到僅發行 3 期的儲蓄券及樣張外，也透過台灣省政府公報及中央日報等記載及報導，釐清儲蓄券發行的來龍去脈，顯見當時的政治強制力及肅殺之氣。