For bothsamples ,the match is performed in Years T－1，T+1， T+2 separately, t statistics are corrected forcross-sectional and time-series correlation using a two-way cluster at the firmand year level.

Wecluster the standard errors at both the firm and year level to obtain standarderrors that are robust to heteroskedasticity,serial correlation andcross-sectional correlation(Petersen,2009; Gow et al.,2010).

请翻译这两段话，并告诉我什么是是two-way cluster？用什么软件的什么功能做two-way cluster？谢谢各位！