https://en.m.wikipedia.org/wiki/Kuns
History 部分最后一段的文字
"According to one version, the tribe Toksoba referred to various primary sourc
es, was Kuns, and this period corresponded to the Don Polovtsians."
这段文字的这一句
"the tribe Toksoba referred to various primary sources, was Kuns"
想问这句话该怎么翻译 文法上怎么解读呢@@

the tribe Toksoba (referred to various primarysources) was Kuns

想问一下 referred 前面有省略关代吗