What books are worth reading for helpdesk/support service methodology, customer focus and conflict resolution?

Question

Books

Hello!
Actually, I want literature on how to competently build a technical support / helpdesk process.
I also want literature on a competent business foreign language (any language), on the art of communicating with a client and getting out of conflict situations that so often arise in the process of a supporter :)
The language of the books is Russian and English. Well, you can and others, if there is really valuable information.
I found something similar on Amazon, but I want to hear the advice of experienced people before turning out my wallet.

Answer 1

The ITIL® Service Strategy Book
The ITIL® Service Design Book
The ITIL® Service Transition Book
The ITIL® Service Operation Book
The ITIL® Continual Service Improvement Book

Answer 2

Passed by, saw the question, below are a few personal recommendations (I hope they will be useful either to those who come across this topic later, or to the author, if the question is still relevant).
There is an excellent book Kind regards! about business correspondence - it is quite suitable for technical support, from there you can take the basic principles. There is a translation into Russian.
Not books, but also useful / interesting:
1) There is such an article about the global vision of the technical support department: https://habr.com/company/cloud4y/blog/421487/ .
This article helped me at one time, it describes useful metrics well: https://habr.com/company/parallels/blog/322374/
2) I myself went through and sent my entire team to such courses:register.businesswriting.com/product-p/495.htm or register.businesswriting.com/product-p/497.htm (see the programs of both to see which one to choose). I don't know if they use such a scheme now, but 2-3 years ago you were "guided" by a teacher - i.e. in addition to the theory for each lesson, there was also the practice of writing response letters to clients, after which the teacher commented on your answers (for example, where is it better to "smooth" or paraphrase). I myself took a lot of good super-polite phrases in business English from there, which are good for extreme cases (for example, enraged customers when you have to apologize to them as politely as possible and, as they say, in full :))))
3) About interesting features of building processes in the department and what features you can apply in your own, oddly enough, the Zendesk blog and their webinars help. They describe some things (for example, "10 tips on how to create a knowledge base so that clients themselves can search and learn everything in it without pulling your team with questions"), then these articles can be dissected and at least a couple of such tips can be dragged to you and embed :)
(the latter is suitable if you use Zendesk or similar)