How to use refer to previous literature/researches in research papers?

Question

I am talking about the topic Singapore English and I want to briefly survey the previous researches on the same topic. Do the following sentences sound natural in English?

1. In literature on Singapore English, Crew (1997) was among the first to observe non-standard tense marking. Subsequently, Alsagoff and Ho (1998) ...
2. Previous researches on Singapore English, Crew (1997) was among the first to observe non-standard tense marking. Subsequently, Alsagoff and Ho (1998) ...
3. Previously, Crew (1997) was among the first to observe non-standard tense marking. Subsequently, Alsagoff and Ho (1998) ...
4. Crew (1997) was among the first to observe non-standard tense marking in Singapore English. Subsequently, Alsagoff and Ho (1998) ...

How else could I start a paragraph that intends to briefly survey/overview previous literature on a certain topic?

Answer 1

First a general comment; I would use Singaporean English rather than Singapore English, in the same way that one refers to American English and not America English.

Your number 1 sounds acceptable to me with the addition of an article: "In the literature ...". Number 2 sounds ungrammatical. Number 3 seems to have an element of tautology; 1997 is clearly prior to the present day, so I think that it is both unnecessary, and odd, to say "Previously". Number 4 sounds just fine; it avoids the strange sounding "previously", and the words "subsequently" clearly and sensibly refers to a time later than that of Crew.