C and the 8051 is a 460-page, ~7 1/2" x 9 1/2" soft-cover book produced on a POD (print on demand) basis by a printer (Lightning Source) with plants in Tennessee in the USA and in the UK. Any copies you order will be produced and shipped from the nearer location. Single copies cost $39.00 US plus postage from the print location and should be produced within 2 weeks. Multiple copies for bookstores and other resellers are available at a discount--contact the me for details. 

To order the book directly from AMAZON:  

http://www.amazon.com/C-8051-4th-Thomas-Schultz/dp/0978399501/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1219055617&sr=8-1

For bookstore reference: 

ISBN 978-0-9783995-0-4

to contact ME
 (for questions about bookstore/resale quantity orders, personal technical questions, 
comments about the book, to request an educator examination copy, or just to chat):

Mailing Address: Wood Islands Prints, 670 TCH RR1, Belle River, PE C0A 1B0 Canada

Phone: (902) 962-3335

Email: schultz@pei.sympatico.ca

to contact silicon Labs
 (to purchase the 8051F020 target board and development kit  for (I believe) $79 US plus shipping):

http://www.silabs.com/tgwWebApp/appmanager/tgw/tgwHome?_nfpb=true&_pageLabel=GenericContentPage&contentObjectId=/public/web_content/products/Microcontrollers/en/C8051F020DK.htm