Johan Oskar Backlund
| Johan Oskar Backlund |
| Onye na-enyocha mbara igwe nke mba Swedish-Russian |
Ọrụ
edit- "Encke's Comet 1895–1908" in Ọkwa kwa ọnwa nke ọgbakọ Royal Astronomical , mbiputa nke iri asaa, ibe akwụkwọ nke nari anọ ná iri abụo na iteghete wee ruo na narị anọ na iri anọ na abụọ n'afọ (1910)