Welbound Perfect Binding Machines
Range of Book Binding, Perfect Binding, Signature Gathering, perfect binding and three knife trimming machines from India's No 1 manufacturers.
http://www.welbound.com/

Binding Technology, Inc.
BindTech Inc is a full service trade bindery providing book manufacturing services including perfect binding, deluxe binding and specialty packaging.
http://www.bindtechinc.com/

Universal Bookbindery, Inc.
Home of Universal Book Bindery
http://www.universalbookbindery.com

Area Trade Bindery
Offers perfect binding, PUR, layflat, stitching, map folding, gluing, wire-O, and spiral binding.
http://www.areatradebindery.com

Your Bindery
One of Denver's most complete Bindery Services. We offer Perfect Binding, Saddle stitched booklets, 3 knife trimmer, folding, Letterpress, Straight collating, Double Loop Wire, Plastic Spiral, Round Cornering, Spine Tape Binding, Drilling, Tabbing, Shrink Wrapping, and FREE POPCORN.
http://www.yourbindery.com

Coverbind Corporation
Create perfect bound documents at the home or office with a document binding system and binding covers by Coverbind.
http://www.coverbind.com/

Dekker Bookbindings
We are an independent case bindery specializing in case binding, perfect binding, and folding. We have been in the book binding business for over 70 years. We partner with book printers throughout the United States and Canada to provide excellent service in the graphic arts industry. Your partner in finishing. book, books, binding, bind, book binding, print, perfect bind, case bind, casebind, foil stamp, sewn, sewn casebind, compact, bookbinding, bindery, trade bindery, smyth sewing, book manufacturing, book printing, book design, graphic arts, bibles, book publishing, publishing, book finishing, finishing, glue, PVA, cold glue, hot glue, PUR, leather bound, backbone, book cloth, cover material, chipboard, collate, gather, sew, trim, hot foil stamp, stamping, signatures, fold, gathering, deboss, dust jacket, dust cover, endsheets, headbands, hot melt, cold melt, hubs, reinforce, round back, tight back, roundback, tightback, sig, smash, spine, square, squareback, super, three piece case, 3-piece case
http://www.dekkerbook.com/

Perfect Document Creation
Perfect document creation is something every company aspires to. Whether its Coil, Spiral, Wire or Fastback binding PDC Presentation Solutions have creative and cost effective binding, finishing and laminating equipment to suit all business types.
http://www.pdcuk.com

Renz Group
RENZ ist führender Hersteller von Stanzsystemen, Bindesystemen und Laminiersystemen. Systeme für alle Aufgabenstellungen im Büro, Copyshop bis zur papierverarbeitenden Industrie.
http://www.renz.com

On a Generalization of Perfect Numbers
J. L. Pe introduces perfect numbers relative to an arithmetical function f. Under this scheme, the usual perfect numbers are just one among many species of "f-perfect numbers". Several open problems and examples of perfect number sets are given, as well as a few f-amicable pairs.
http://www.geocities.com/windmill96/fperfect/fperfect.html