TY  - BOOK
AU  - Tetley,L.
AU  - Calcutt,D.M.
TI  - Electronic aids to navigation: position fixing 
SN  - 0340543809
PY  - 1991///
CY  - London : 
PB  - E. Arnold, 
KW  - Electronics in navigation
N1  - Includes index
ER  -