Princeton Language Institute

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  10 Days to a More Powerful Vocabulary
  by Princeton Language Institute Staff, Tom Nash
  Softcover, Grand Central Publishing, ISBN 0446676691 (0-446-67669-1)
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  10 Days to a Sharper Memory
  by Philip Lief Group, Princeton Language Institute, Russell Roberts
  Softcover, Grand Central Pub, ISBN 0446676667 (0-446-67666-7)
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  10 Days to More Confident Public Speaking
  by Philip Lief Group, Princeton Language Institute, Lenny Laskowski
  Softcover, Grand Central Pub, ISBN 0446676683 (0-446-67668-3)
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  21st Century Grammar Handbook
  by Princeton Language Institute
  Softcover, Bantam Books, ISBN 0440214475 (0-440-21447-5)
  More editions of 21st Century Grammar Handbook:
  • The Princeton Language Institute 21st Century Dictionary of Acronyms and Abbreviations: Softcover, ibooks, Incorporated, ISBN 0743486870 (0-7434-8687-0)
  • Webster's 21st Century Large Print Dictionary: Softcover, Dell Publishing, ISBN 0385316437 (0-385-31643-7)
  • 21st Century Grammar Handbook: Softcover, Dell Publishing, ISBN 0440215080 (0-440-21508-0)
  • 21st Century Mispeller's Dictionary: Softcover, Dell Publishing, ISBN 0440215455 (0-440-21545-5)
  • 21st Century Dictionary of Acronyms and Abbreviations: Softcover, Dell Publishing, ISBN 044021548X (0-440-21548-X)
  • 21st Century Guide to Improving Your Writing: Softcover, Dell Publishing, ISBN 044021727X (0-440-21727-X)
  • 21st Century Synonym and Antonym Finder: Hardcover, Demco Media, ISBN 0606050973 (0-606-05097-3)
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  The 21st Century Office Assistant's Manual
  by Philip Lief Group, Princeton Language Institute
  Softcover, Bantam Dell Pub Group, ISBN 044061368X (0-440-61368-X)
  More editions of The 21st Century Office Assistant's Manual:
  • The 21st Century Office Assistant's Manual: Softcover, Dell Publishing, ISBN 0440217253 (0-440-21725-3)
  • 21st Century Office Assistants Manual: Softcover, Dell Publishing, ISBN 044061371X (0-440-61371-X)
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  via
  Roget's 21st Century Thesaurus: In Dictionary Form
  by Barbara Ann Kipfer, Princeton Language Institute, Peter Mark Roget, the Princeton Language Institute
  Softcover, Bantam Dell Pub Group, ISBN 0385312555 (0-385-31255-5)
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  via
  Roget's 21st Century Thesaurus: The Essential Reference for Home, School, or Office
  by Barbara Ann Kipfer, Princeton Language Institute, Peter Mark Roget
  Softcover, Bantam Dell Pub Group, ISBN 038533415X (0-385-33415-X)
  More editions of Roget's 21st Century Thesaurus: The Essential Reference for Home, School, or Office:
  • Roget's 21st Century Thesaurus: In Dictionary Form The Essential Reference for Home, School, or Office: Softcover, Bantam Books, ISBN 0440215552 (0-440-21555-2)
  • Roget's 21st Century Thesaurus: The Essential Reference for Home, School, or Office: Softcover, Bantam Books, ISBN 0440235138 (0-440-23513-8)
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  The Spell Well Dictionary for the 21st Century
  by Barbara Ann Kipfer
  Softcover, ibooks, Incorporated, ISBN 0743486994 (0-7434-8699-4)
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  Twenty-First Century Guide to Building Your Vocabulary
  by Elizabeth Read, Princeton Language Institute Staff, Philip Lief Group Inc. Staff
  Softcover, Dell Publishing, ISBN 0440217210 (0-440-21721-0)
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  The Twenty-First Century Manual of Style
  by Princeton Language Institute Staff
  Softcover, Dell Publishing, ISBN 0440220742 (0-440-22074-2)