Writing systems: a linguistic approach, Henry Rogers, Wiley-Blackwell, 2005, ISBN 978-0-631-23464-7, ... an alphabet is a writing system in which all phonemes, both consonant and vowels, are represented ... an abjad is like an alphabet, but only consonants are written, not vowels ... in an abugida, the vowels are written as diacritics on the consonants ...
