Valtonen, Mauri J.; Zheng, Jia-Qing; Mikkola, Seppo (March 1992). "Origin of oort cloud comets in the interstellar space". Celestial Mechanics and Dynamical Astronomy. 54 (1–3): 37–48. Bibcode:1992CeMDA..54...37V. doi:10.1007/BF00049542. S2CID189826529.
Valtonen, Mauri J.; Zheng, Jia-Qing; Mikkola, Seppo (March 1992). "Origin of oort cloud comets in the interstellar space". Celestial Mechanics and Dynamical Astronomy. 54 (1–3): 37–48. Bibcode:1992CeMDA..54...37V. doi:10.1007/BF00049542. S2CID189826529.
Valtonen, Mauri J.; Zheng, Jia-Qing; Mikkola, Seppo (March 1992). "Origin of oort cloud comets in the interstellar space". Celestial Mechanics and Dynamical Astronomy. 54 (1–3): 37–48. Bibcode:1992CeMDA..54...37V. doi:10.1007/BF00049542. S2CID189826529.