21
by Moulton, Hugh Fletcher
Published 1913
Butterworth
...Letters patent for inventions...

26
by Frost, Robert
Published 1906
Stevens and Haynes
...Law and practice relating to letters patent for inventions...

27
by Frost, Robert
Published 1912
Stevens and Haynes
...Law and practice relating to letters patent for inventions...

31
by Forbes of Pitsligo, Alexander Forbes
Published 1751
s.n
Subjects: ...Letters patent / Scotland / Early works to 1800...