APA (7th ed.) Citation

Hardy, C. The Aural System Being the Most Direct, the Straight-Line Method for the Simultaneous Fourfold Mastery of a Foreign Language.

Chicago Style (17th ed.) Citation

Hardy, Charles. The Aural System Being the Most Direct, the Straight-Line Method for the Simultaneous Fourfold Mastery of a Foreign Language.

MLA (9th ed.) Citation

Hardy, Charles. The Aural System Being the Most Direct, the Straight-Line Method for the Simultaneous Fourfold Mastery of a Foreign Language.

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