The characteristics of the different Sur colours.

Salovatov, O., (1991). Ovtsevodstvo(No. 2), 32-33. Russian language

Interaction of A, E, Sb, and Ss gene alleles in formation of sur coloration in sheep.

Aliev, G. A., Rachkovskiĭ, M. L., (1986). Soviet Agricultural Sciences(No. 7), 43-47. English language

Relatiewe ekonomiese belangrikheid en oorerflikheid van sekere eienskappe van bruin Karakoelpelse. / Relative economic importance and inheritance of some characters of brown Karakul pelts.

Gouws, D. J., (1974). South African Journal of Animal Science 4(2), 209-212. Afrikaans language