The claim that monotonic transformations preserve the ordinal properties of utility functions is a standard definitional property in microeconomic theory and utility theory, making it common knowledge that requires no citation.
The claim states a foundational, definitional fact of microeconomic theory: ordinal utility represents preferences up to strictly increasing (monotonic) transformations, meaning the ranking of options is entirely preserved. None of the retrieved papers specifically test or contest this foundational definition; instead, they discuss distinct statistical, machine learning, or reliability topics. Therefore, this is classified as common knowledge.