As can be expected, there is no shortage of books written about Tientsin during the 85 year period of the foreign concessions that existed there.
One book stands out above all as being the definitive work on the subject. It is O. Rasmussen's Tientsin - An Illustrated Outline of History, published in 1925.
Long out of print, it is very hard to come by, but there are copies in libraries. I saw one at the City of London Library and another at the Seattle Public Library.
Here are some little known titles with fine and accurate descriptions of Tientsin of the period.
Please Don't Walk On My Grave, Part 2, by Vera Skoblin.
An Edge In Wordways, by Richard Dyott.
Grace in China, by Eleanor Cooper and William Liu.
Passport For China, by Alexander Burgess.
Shanhaikwan, by Iolanda Gironi Morante.
Avshalomov's Winding Way, by Jacob and Aaron Avshalomov.
Honourable Stomach Is Empty, by Tom Henling Wade.