The cultural development of Bulgaria
Foreign Language Press, 1959
 Buku Teks SO
Harrington, Rick
Stress, health and well-being: thriving in the 21st century
Wadsworth and Cengage Learning, 2013
 Buku Teks SO
Simsir, Bilal N.
The Turks of Bulgaria (1878-1985) / Bilal N. Simsir
K. Rustem , 1988
 Buku Teks SO
Saxena, H.L.
Bulgaria under the red star / H.L. Saxena
S. Chand & Co, 1957
 Buku Teks SO
Sartono Kartodirdjo, 1921-2007
Protest movements in rural Java : a study of agrarian unrest in the Nineteenth and early Twentieth centuries
Oxford University Press, 1978, 1973
 Buku Teks SO