Linked from
The 14 pages that link to Vowel, each with the reason it gives.
Great Vowel ShiftNarrower topic: The shift affected the quality of English long vowels.
AssonanceNarrower topic: Assonance depends on recurring vowel sounds, not on matching letters.
DiphthongNarrower topic: A diphthong is a changing kind of vowel sound.
Mid central vowelNarrower topic: Mid central vowels belong to this broad class of speech sounds.