https://receivedpronunciation.thinkific.com/courses/british-english-pronunciation-received-pronunciation

https://en.wikipedia.org/wiki/International_Phonetic_Alphabet

https://en.wikipedia.org/wiki/Received_Pronunciation

https://en.wikipedia.org/wiki/IPA_vowel_chart_with_audio

https://en.wikipedia.org/wiki/IPA_pulmonic_consonant_chart_with_audio

容認発音（クイーンズ イングリッシュ）について　(Wikipedia Japan)

容認発音（クイーンズ イングリッシュ）について(weblio)

http://www.bbc.co.uk/learningenglish/english/features/pronunciation/longvowel1