Hi I thought I had a copy of the G.R.G. Worcester book you are looking for but I don't instead I have an interesting book by Ivon A Donnelly first published in 1924 & titled "CHINESE JUNKS AND OTHER NATIVE CRAFT". The book covers from the Yellow River Junk in the north to theban Ch'uan Junk from the Kan Kiang River in the south and a lot in between Pechili Trader,The Ningpo Trader to the HongKong Traders & Donnelly does spell it that way always.  It was republished in 1988 in Singapore by Graham BrashPTE LTD 36-C Princep St. Singapore 0718.  The book has both good pen & ink drawings and excellent Gouache I think paintings with an extensive outline of each typesets characteristics, home ports history etc.Apparently Donnelly lived in China for a considerable period & made an extensive study of the many variants as possible. He is enthusiastic about junks & seems to have considerable knowledge of them. I'll try & send you some images if you like in the next couple of days.  I lived in Singapore for three years & they do have a quite extensive maritime museum so they might be good to get in touch with. Hopes this helps. Mark

We have all Worcester's books, as well as Ivan Donnelly's in our virtual library, as I have mentioned several times before.  Go to Member's Area/Books & Magazine/JRA Library to download them. "A Classification ..." is very rare.  You would have to be both wealthy and lucky to get your own copy.