Kiyomi Sakamoto Shoichi Aoyama Shigeo Asahara Haruki Mizushina Hirohiko Kaneko Relationship between Emotional State and Pupil Diameter Variability under Various Types of Workload Stress. 177-185 2009 HCI (15) http://dx.doi.org/10.1007/978-3-642-02731-4_21 conf/hci/2009-15 db/conf/hci/hci2009-15.html#SakamotoAAMK09