Smirnitsky, A.I.
Higher School Publishing House, 1975
Buku Teks
Rafif Aufa Nanda
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2020
UI - Makalah dan Kertas Kerja
Potapova, Nina F.
Progress Publishers, [196-]
Buku Teks SO
Lusin, Natala
Baron's Education, 1992
Buku Referensi
Timberlake, Alan
Cambridge University Press, 2004
Buku Teks SO