This claim is a matter of standard historical common knowledge regarding medieval feudal demographics and governance, requiring no specific citation.
The claim that medieval peasants rarely met the king is a self-evident historical reality given the vast demographic imbalance, lack of mass transit, and local nature of feudal power structures. None of the retrieved papers specifically evaluate or test this historical commonplace; they are off-topic studies concerning colonial science, South Asian history, Irish bioarchaeology, and medieval Iberian local agency. Therefore, it is categorized as common knowledge.