Terrestrial navigation 2 
Ynion, Eugenio J. 
 -  Philippine Foundation for Maritime Teaching Aids, Inc.  2003 
 - vi, 116 pages ;. 
9-71030606-5
Navigation.
M 623.89 Y6t 2003, r2011
                        9-71030606-5
Navigation.
M 623.89 Y6t 2003, r2011