TY - JOUR T1 - Navigator Notes JF - NAVIGATION: Journal of the Institute of Navigation JO - NAVIGATION SP - 239 LP - 242 DO - 10.1002/navi.434 VL - 68 IS - 2 AU - Richard B. Langley Y1 - 2021/06/20 UR - https://navi.ion.org/content/68/2/239.abstract N2 - ER -