also: レファレンスブック
noun
A book intended to be consulted for specific information rather than read cover to cover, such as a dictionary, encyclopedia, or handbook.
このリファレンスブックはプログラミングの用語を調べるのに便利だ。
This reference book is handy for looking up programming terms.
参考書 is a more general term for a reference work or study aid, often used for exam preparation, while リファレンスブック is a direct loanword typically used for specialized or technical reference books.
便覧 is a handbook or manual, often more compact and practical, whereas リファレンスブック can be any size and is more formal.
Loanword from English 'reference book'.