‘The Legend of Perak, part I’ tells of Perak in the Beruas/Gangga Negara-era, as well as an abridged version of the Malay Annals (Sejarah Melayu). Click HERE for the .pdf file.
Source: R.J. Wilkinson. Papers on Malay Subjects: Part II – Notes on Perak History. FMS Government Press, 1908.