Saudagar-Saudagar Cina Pulau Pinang Di Kedah, 1890 – 1910 - Lim, Thean Boon (Universiti Sains Malaysia, 1989)
The report of the census of population for Kedah and Perlis in 1911 showed that in the year, there were 88,491 Kedah Malays engaged in agricultural occupations. Out of this number, •88,121 or 99.5% were padi planters". Menurut Frank Swettenham, "The padi fields are of greater extent than any that I have seen elsewhere in Peninsula". Gambaran yang diberi ke atas penanaman padi nampalmya begitu mengkagumkan iaitu penanaman padi yang dijalankan secara besar-besaran Penanaman padi sudah dijalankan secara besar-besaran sebelum kedatangan orang Cina secara beramai-ramai pada akhir kurun ke 19.