We will be du-u-mb!
"April Hopes"
William Dean Howells Last Updated: February 27, 2009
The letter b then came at the end of the word; but as the combination mb, followed by nothing was unstable, b was soon lost in pronunciation.
"The English Language"
Robert Gordon Latham
Type M has two other sub-types Ma and mb.
"Lectures on Stellar Statistics"
Carl Vilhelm Ludvig Charlier