@BOOK{ Book!D - 90242941,
AUTHOR = " Saul Stahl.",
TITLE = "A gateway to modern geometry :",
LIBRARY= "مرکز و کتابخانه مطالعات اسلامی به زبان‌های اروپایی",
SUBJECT = "Geometry, Non-Euclidean.,Geometry, Non-Euclidean.,Hyperbolische Geometrie.",
URL = "/book/90242941/A-gateway-to-modern-geometry/"}