@BOOK{ Book!D - 94051854,
AUTHOR = "/ by Alfred North Whitehead and Bertrand Russell",
TITLE = "Principia mathematica, to 56",
LIBRARY= "كتابخانه مركزی و مركز اسناد دانشگاه مازندران",
SUBJECT = "Mathematics- Philosophy,Logic, Symbolic and mathematical",
URL = "/book/94051854/Principia-mathematica-to-56/"}