Sextant and LOP Accuracy
American Practical Navigator, H. O. 9  (1962), Page 417
Air Navigation, H.O. 216 (1941)
Page 182
Page 183
Air Navigation, AFM 51-40 (1951), Page 206
The American Air Navigator ,  Dohm (1958),  Page 109
Air Navigation, Weems (1938)
Page 313
Page 314 & 315
Page 316
Page 362 & 363
Page 364 & 365
Page 424 & 425