@BOOK{ Book!D - 100974751,
AUTHOR = "/ by Alfred North Whitehead and Bertrand Russell",
TITLE = "Principia mathematica to 56",
LIBRARY= "كتابخانه پردیس علوم (دانشگاه تهران)",
SUBJECT = "Mathematics -- Philosophy,Logic, Symbolic and mathematical",
URL = "/book/100974751/Principia-mathematica-to-56/"}