a _ -
Stratford, William Samel. Now 21 in xxE.220a.20 On the elements of the orbit of Halley's comet, at its appearance in 1835 and 1836.
London, 1837. 81 pp. Tables. 8°. From the Nautical almanac for 1839 (+x8-138.1 (1839) }.
- Comets. = Halley, ly) Edmund. ~ 1656-1742.