APA (7th ed.) Citation

Smith, R. (2016). American English: OO vowel : how to make the OO vowel. Rachel's English.

Chicago Style (17th ed.) Citation

Smith, Rachel. American English: OO Vowel : How to Make the OO Vowel. Philadelphia, PA: Rachel's English, 2016.

MLA (9th ed.) Citation

Smith, Rachel. American English: OO Vowel : How to Make the OO Vowel. Rachel's English, 2016.