Sorry to revive an old thread, but it appears that a new and much-expanded edition of this book is soon to be released by Harvard University Press - will Pleco be able to update the current version to include the new material? I'd be happy to repurchase the book, even. Having this in digital form is absolutely invaluable as someone working in the field.
The new edition will have two volumes, of 1000 pages each (which means the total number of pages will increase by roughly 700 from the current fifth edition):
https://www.hup.harvard.edu/catalog.php?isbn=9780674260184
https://www.hup.harvard.edu/catalog.php?isbn=9780674260191
The new edition will have two volumes, of 1000 pages each (which means the total number of pages will increase by roughly 700 from the current fifth edition):
https://www.hup.harvard.edu/catalog.php?isbn=9780674260184
https://www.hup.harvard.edu/catalog.php?isbn=9780674260191