求助大家翻译一下,不要在线啊,不要在线,谢谢,英语翻译

求助大家翻译一下,不要在线啊,不要在线,谢谢,英语翻译
A further nine were
suggested by firms which had already taken part in the research. The source of
the remaining 18 was through personal contacts, either direct or indirect, of
members of the research team. While it is recognised that these methods of
selecting the case study firms could lead to an element of bias in the sample,
they did prove to be extremely successful. Only two of the firms which were
contacted declined to participate, and in both cases the reason given was lack
of time.