When the phrase "according to what" feels repetitive, there are plenty of synonyms to use instead. "As per" is a handy one, and can sometimes be shortened to just "per." "In accordance with" is another popular option, and it can sound a bit more formal than the previous one. "Pursuant to" is great for legal or official contexts, while "in compliance with" suggests a bit more flexibility in the original statement. "Based on" is a useful synonym if you want to emphasize that your opinion is informed by something specific. Finally, "following" can be used if you're interpreting or following a set of guidelines or instructions.