APA (7th ed.) Citation

The Barker index of crystals: A method for the identification of crystalline substances. Heffer.

Chicago Style (17th ed.) Citation

The Barker Index of Crystals: A Method for the Identification of Crystalline Substances. Cambridge: Heffer.

MLA (9th ed.) Citation

The Barker Index of Crystals: A Method for the Identification of Crystalline Substances. Heffer.

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