These books offers a commands of the basic principles of perspective that is essential to creating dynamic, plausible compositions. With a user-friendly approach, this step-by-step guide will help you master the basics like scale drawing, contour line drawing, linear perspective, tone and texture, and more.

http://www.rarefile.net/htx3tcdi3ujo/Freehand.Perspective.and.Sketching.pdf
http://www.rarefile.net/o0si4s6k4d4w/Pencil.Sketching.2nd.Edition.pdf
http://www.rarefile.net/yxex7pdiqo4d/Pencil.Sketching.pdf
http://www.rarefile.net/g8p907blguzz/Perspective.Sketching.Freehand.and.Digital.Drawing.Techniques.for.Artists.and.Designers.pdf
http://www.rarefile.net/9lchm1y8ari8/Sketch.based.Interfaces.and.Modeling.pdf
http://www.rarefile.net/w9ob5c6kmbim/Sketch.Book.for.the.Artist.pdf
http://www.rarefile.net/9s7p4sez7uz4/Sketching.Drawing.Techniques.for.Product.Designers.pdf
http://www.rarefile.net/ltd3ngx9bs6e/Sketching.People.Life.Drawing.Basics.pdf
http://www.rarefile.net/2qhhdwnn74tr/Sketching.User.Experiences.pdf
.