Nicholas Belfield Dennys: 初學階. Ch’o hok kai. A handbook of the Canton vernacular of the Chinese language : being a series of introductory lessons, for domestic and business purposes (London: Tübner & Co./Hong Kong „China Mail“ Office 1874)
- Digitized: Internet Archive (Book contributor: Cornell University Library, digitizing sponsor: MSN)
- Bibliographic reference: BS 1694, Löwendahl 1440
- No copy listed in Wiener China-Bibliographie