http://repository.uhamka.ac.id/4489/ Bambang, Dwi Hartono http://repository.uhamka.ac.id/4489/1/Buku%206%20Langit-langit%20Harapan.jpg Bambang, Dwi Hartono LANGIT-LANGIT HARAPAN. MM UHAMKA. ISBN 978-602-48225-3-8 (Submitted)