In this website you can find information about literature on Chinese and German philately.
In addition, you'll find a comprehensive review of the market situation by hammer prices for which these entires were finally sold at international auctions.
The entires are described in brief but exponentially and - and this is the special value of this catalogue - for each of them is shown the price, to be exact: the price this item was sold for by one of the auction companies. So you will have real prices and not only estimates. If you add further 20 to 25 percent (auction surcharges) you will exactly know what this card or cover is worth or at least was worth a buyer.
In China Philately Vol. I you'll find the images of several hundreds of covers and postcards of the Foreign Post Offices in China at the turn of the century. Many of the Russian mail cancels are described in detail according to Tchilinghirian.
On 365 pages of the Vol. II are shown about 1,000 b/w pics of covers and cards of the Chinese Empire issues.
In Vol. III you'll find the images of 750 covers and postcards of Hong Kong, Macao, Taiwan and Tibet.