Book Recommendations for Speech Disorders

[Tigerlion]

The SALT suggests that my DS (aged 3.3 years) has a speech disorder and that his delay of comprehension is 18 months and delay of speech is 12 months. We are hoping that he can go to a special language unit within a mainstream school.
Can anyone recommend any good books about speech disorders so that I can gain a better understanding and hopefully get additional exercises to what the SALT is recommending.

Thanks

Agree with TClanger. Once he hits three his mum will most likely find that the professionals start taking this a lot more seriously, and be keen to do referals. (3 tends to be a thresshold age, as in where if a child is just a bit late, but will sort themselves out without outside help, it usually has happened by then).