第1篇
http://www.jstor.org/pss/40215919?searchUrl=%2Faction%2FdoAdvancedSearch%3Fq0%3Dtobin%2Beffect%26f0%3Dti%26c1%3DAND%26q1%3D%26f1%3Dall%26wc%3Don%26Search%3DSearch%26sd%3D%26ed%3D%26la%3D%26jo%3D&Search=yes
第2篇
http://www.jstor.org/pss/3549034?searchUrl=%2Faction%2FdoAdvancedSearch%3Fq0%3Dtobin%2Beffect%26f0%3Dti%26c1%3DAND%26q1%3D%26f1%3Dall%26wc%3Don%26Search%3DSearch%26sd%3D%26ed%3D%26la%3D%26jo%3D&Search=yes