The book in question is A Textbook in Classical Tibetan by Joanna Bialek. Bialek learned Classical Tibetan from Michael Hahn's Lehrbuch der klassischen tibetischen Schriftsprache (1996) and also translated that book into Polish. Her own textbook builds on that experience as well as on teaching Classical Tibetan at the Philipps University in Marburg (Germany). This means the book is very different from Joe Wilson's Translating Buddhism from Tibetan.
I did a year of Classical Tibetan in the 90s using Hahn's Lehrbuch at uni and have good memories of it, except it being in German was a pain in the butt. Having done nothing with Tibetan in the meantime, I recently purchased a copy of Bialek's book to finally make work of learning to read Classical Tibetan for real this time. I read Wilson's book recently and look forward to comparing the two approaches.
From the publisher (Routledge):
A Textbook in Classical Tibetan is the first comprehensive course book in the Classical Tibetan language written in English. The textbook describes the grammar of pre-16th-century Classical Tibetan works for beginners and students of intermediate level. It is intended to cover the most essential topics that can be mastered within two semesters of an academic class. Classical Tibetan is a written Middle Tibetan language that has been in use in Tibet from the 9th century. Until the early 20th century it served all purposes, from administrative, to medical, to religious. Nowadays Classical Tibetan remains an important part of religious identity and services for communities also outside of cultural Tibet, foremost in India, Nepal, and Bhutan, but also elsewhere, most importantly in Europe, North America and Australia.
The main body of the textbook consists of an introduction to the Tibetan script, eighteen lessons, and a reading section. Each lesson elucidates several grammatical topics which are followed by an exercise and a word list. The chapter readings contain four supplementary readings. In addition to the main parts of the textbook, a brief introduction to Tibetic languages provides linguistic context for the language taught in the textbook, whereas the chapter Translations of Exercises and Readings contains translations and explanatory notes to the exercises provided at the end of each lesson, as well as to the readings.
A Textbook in Classical Tibetan is essential reading for both undergraduate and graduate students without any knowledge of Classical Tibetan, but also for those who would like to deepen their experience of the language by reading annotated excerpts from well-known pieces of Tibetan literature.
A positive review from Buddhist Digital Resource Center: