en.wikipedia.org/wiki/Critical_Path_(book)

Authoritative library records consistently classify Critical Path at Dewey 909.82, not "909 19."

• The Free Library of Philadelphia's MARC record for the book shows 082 00 |a 909.82 |2 19. In MARC cataloging, |a 909.82 is the Dewey number, while |2 19 indicates the 19th edition of the Dewey Decimal Classification used to assign it.
• Open Library's edition record for the 1981 St. Martin's Press edition also lists Dewey Decimal Class 909.82.

So the article's 909 19 appears to be a malformed reading of 909.82 |2 19, where the edition marker 19 was mistakenly treated as part of the classification number.

The article's Library of Congress classification is wrong at the class level.

Authoritative catalog records place Critical Path in CB428, not CB19:

• The Free Library of Philadelphia's MARC record shows 050 00 |a CB428 |b .F85 1981.
• Open Library's 1981 edition record, which incorporates library catalog source records, lists the Library of Congress classification as CB428 and CB428 .F85 1981 (and also notes CB428 .F84 in another source record).

There is some minor variation in the cutter suffix (.F84 vs .F85) across records, but the key point is not disputed: the book is cataloged under CB428, not CB19. That makes CB19 .F84 1981 incorrect.