In March 2004 I published a book about shirt numbers. Available in English and in Dutch. The book can be ordered by mailing to info(at)letterbeeld(dot)nl. The price is 8 euro plus shipping costs. International payments only by PayPal.
A study about the history of the shirt of the Dutch national football team was carried out by Maaike Gotschal and Uli Schuster. They also developed new ideas for the design of the shirt. The results of the study are published on www.oranjehemden.nl.
There are many sites on the internet where you can view and buy fonts. The most extensive overview is given by MyFonts.
The shirt number book. 48 pages, 14x17 cm, hardcover edition.