The part of the sentence "several papers were" is correct and usable in written English.
You can use it when referring to items of written documents or related materials. For example: Several papers were presented at the conference on the topic of political economy.
Several papers were quick to point out on Saturday that none of the club's January signings – Mario Bolatti, Felipe, Adem Ljajic, Keirrison and Harris Seferovic – started against Samp, and only Ljajic made it off the bench.
Then several papers were devoted to the topic.
Recently, several papers were presented proposing adaptive Tikhonov regularization parameters, instead of constant ones.
In recent years, for fractional semilinear control systems in Banach spaces, several papers were devoted to the approximate controllability.
Several papers were also pleased by the fact that with the exception of Israel's delegation, there was no mass walkout, as there was with last year's UN speech by Mr Rouhani's predecessor, Mahmoud Ahmadinejad.
Several papers were then published regarding analytical approaches to assess heparin purity [13], [22], [23], [24], [25], [26].
In France, several papers are kept alive by public subsidies.
In France, for instance, several papers are kept alive by public subsidies, which the government of President Nicolas Sarkozy recently moved to increase.
And finally, several papers are raising questions over prison security in the country after a man broke out of a jail in southern China.
Several papers are available dealing with the influence of the operating parameters on the scratch behaviour of polymers.
Several papers are focusing on the therapeutic effects of CTLs in different cancers using novel approaches targeting tumor-specific CTLs.
