APA (7th ed.) Citation

Firsoff, V. A. (1974). Working with gemstones. David and Charles.

Chicago Style (17th ed.) Citation

Firsoff, Valdemar Axel. Working with Gemstones. Newton Abbot: David and Charles, 1974.

MLA (9th ed.) Citation

Firsoff, Valdemar Axel. Working with Gemstones. David and Charles, 1974.

Warning: These citations may not always be 100% accurate.