TOLKIEN’s LANGUAGES (General):
The Elvish Writing Systems of J.R.R. Tolkien
A Secret Vice: Tolkien on Invented Languages
From Elvish to Klingon: Exploring Invented Languages
BOOKS ABOUT TRANSLATING / READING TOLKIEN IN OTHER LANGUAGES:
Tolkien Through Russian Eyes
Tolkien in Translation
Tolkien and Sanskrit (second, expanded edition): The Silmarillion in the Cradle of Proto-Indo-European
Tolkien and Welsh (Tolkien a Chymraeg): Essays on J.R.R. Tolkien's Use of Welsh in his Legendarium
Tolkien and Wales: Language, Literature and Identity
La Conexión Española de J.R.R. Tolkien. El Tío Curro
SINDARIN:
A Fan's Guide to Neo-Sindarin: A Textbook for the Elvish of Middle-earth
A Gateway to Sindarin: A Grammar of an Elvish Language from JRR Tolkien's Lord of the Rings
Sindarin-English English-Sindarin Dictionary
Pedin Edhellen (Sindarin Course)
Elbisch für Anfänger: Der Sindarin-Kurs (German Edition)
Das große Elbisch-Buch (German Elvish - German Dictionary)
Curso De Sindarin (in Portuguese)
O Sindarin Reunido, Uma compilação do Élfico Cinzento (Portuguese Edition)
QUENYA
Quenya course (pdf)"
Lingue elfiche. Quenya e Lindarin *Italian Sindarin Dictionary)
Elvish Dictionary Quenya-English English-Quenya
Elvish Verb Chart - Quenya
La lengua de los elfos: una gramática para el quenya de J. R. R. Tolkien (Quenya Couse in Spanish)
Quetin i lambë Eldaiva (Quenya Course)
Curso de Quenya: A Mais Bela Lingua dos Elfos (in Portuguese)
WESTERENESSE:
Words of Westernesse: Tolkien's Languages of Men and Hobbits
TOLKIEN DICTIONARIES IN SEVERAL LANGUAGES:
Das große Mittelerde-Lexikon. Ein alphabetischer Führer zur Fantasy-Welt von J.R.R. Tolkien (Middle Earth Lexicon in German)
Das neue große Tolkien-Lexikon (German)
Diccionario Tolkien (Spanish Edition)
Dictionnaire Tolkien (French Edition)
Dizionario dell'universo JRR Tolkien (Italian Edition)
Encyclopedie des langues de la Terre du milieu (French Edition)
Bonus Titles about Invented Languages:
Encyclopedia of Fictional and Fantastic Languages
The Art of Language Invention: From Horse-Lords to Dark Elves, the Words Behind World-Building
In the Land of Invented Languages: Esperanto Rock Stars, Klingon Poets, Loglan Lovers, and the Mad Dreamers Who Tried to Build A Perfect Language
The Language Construction Kit by Mark Rosenfelder
Advanced Language Construction
The Conlanger's Lexipedia
Glossopoese - O Complexo e Desconhecido Mundo das Línguas Artificiais
A Dictionary of Made-Up Languages: From Elvish to Klingon, The Anwa, Reella, Ealray, Yeht (Real) Origins of Invented Lexicons