The Complete Spanner's Lambretta Kit Book edition 1 by Martin 'Sticky' Round.
 
If you are thinking of buying a kit for a Lambretta, this is a must read so that you can identify what kit is best for your needs. Sticky takes an indepth look at the different kits available for Lambrettas, tries and tests them to give a verdict.  There are build tips, buying advice and dyno results. It is the most comprehensive review of Lambretta performance upgrades ever compiled.