[1]Diarsipkan 2019-03-30 di Wayback Machine. : "Additionally in the ninth century, the Persian mathematician and geographer, Habash al-Hasib al-Marwazi, utilized the utilization circular trigonometry and guide projection strategies keeping in mind the end goal to change over polar directions to an alternate arrange framework fixated on a particular point on the circle, in this the Qibla, the course to Mecca. Abū Rayhān Bīrūnī (973– 1048) later created thoughts which are viewed as a reckoning of the polar organize framework."
General CartographyDiarsipkan 2017-12-09 di Wayback Machine. : "The Iranian geographers Abū Muhammad al-Hasan al-Hamdānī and Habash al-Hasib al-Marwazi set the Prime Meridian of their maps at Ujjain, a center of Indian astronomy"
"Archived copy"(PDF). Diarsipkan dari versi asli(PDF) tanggal 2013-10-07. Diakses tanggal 2013-09-04.Parameter |url-status= yang tidak diketahui akan diabaikan (bantuan)
General CartographyDiarsipkan 2017-12-09 di Wayback Machine. : "The Iranian geographers Abū Muhammad al-Hasan al-Hamdānī and Habash al-Hasib al-Marwazi set the Prime Meridian of their maps at Ujjain, a center of Indian astronomy"
[1]Diarsipkan 2019-03-30 di Wayback Machine. : "Additionally in the ninth century, the Persian mathematician and geographer, Habash al-Hasib al-Marwazi, utilized the utilization circular trigonometry and guide projection strategies keeping in mind the end goal to change over polar directions to an alternate arrange framework fixated on a particular point on the circle, in this the Qibla, the course to Mecca. Abū Rayhān Bīrūnī (973– 1048) later created thoughts which are viewed as a reckoning of the polar organize framework."
"Archived copy"(PDF). Diarsipkan dari versi asli(PDF) tanggal 2013-10-07. Diakses tanggal 2013-09-04.Parameter |url-status= yang tidak diketahui akan diabaikan (bantuan)