Which two primary publications does STELLA incorporate information from?

STELLA, which stands for "Systems for Training in Electronic Navigation," primarily integrates information from the Nautical Almanac and Sight Reduction Tables to assist navigators in calculating their positions. The Nautical Almanac provides essential astronomical data, such as the positions of celestial bodies and their movements over time, which are critical for celestial navigation. Conversely, the Sight Reduction Tables facilitate the mathematical processes involved in using these celestial observations to calculate one's position at sea.

By combining these two resources, STELLA enhances a navigator's ability to determine their location accurately and efficiently while at sea, making the correct choice of these publications integral to effective navigation practices. The other options mentioned, while relevant to navigation, do not form the core basis for celestial navigation calculations as seen in STELLA.