[ ] Both Margetts et al. (2011) and van de Rijt et al. (2014) performed experiments studying the process of people signing a petition.
[ ] ທັງ Margetts et al. (2011) ແລະ van de Rijt et al (2014) ໄດ້ປະຕິບັດວຽກທົດລອງສຶກສາຂະບວນການຂອງຜູ້ລົງນາມໃນຄໍາຮ້ອງຟ້ອງ.