Extracts from American practical navigator ; an epitome of navigation originally by Nathaniel Bowditch. Published by the U. S. Navy Hydrographic Office under the authority of the secretary of the Navy. - Bowditch, Nathaniel 1773-1838 (Washington, D. C. Manila Govt. Print. Off National Book Store., 1966)
Reprinted under authority of Presidential Decree no. 285
Keywords: Navigation; Nautical astronomy