<prompt> Translate the following text to EnglishKwa kawaida, sisi kutumia mbinu mbalimbali, na mbinu ya ukaguzi trail sasa kupendekezwa kwa ajili ya matumizi ya masomo ya kesi ilikuwa yenyewe kupitishwa kutoka taratibu kama vile ukaguzi kama karatasi za kazi na rejea, ambayo ni kawaida mazoezi na GAO.  <response>: We often use multiple methods, and the audit trail technique now recommended for case study use was itself adopted from such auditing procedures as workpapers and referencing, which are standard practice with GAO. 