Subject: The Principal Triangulation of the South-East Quadrilateral; including the Great Arc; Section 18° to 24°; the East Coast Series; the Calcutta and the Bider Longitudinal Series; the Jabalpur and the Bilaspur Meridional Series; and the details of their Simultaneous Reduction.
Publisher: Office of the Trigonometrical Branch, Survey of India
Subject: General Description of the Principal Triangulation of the North-East Quadrilateral including the Simultaneous Reduction and the Details of Five of the Component Series
Publisher: Office of the Trigonometrical Branch, Survey of India