Helen Keller's letters are important, not only as a supplementary story of her life, but as a demonstration of her growth in thought and expression--the growth which in itself has made her distinguished.
Supplementary to the preceding was the Nova litteraria Germaniae collecta Hamburgi (1703-1709), which from 1707 widened its field of view to the whole of Europe.
The loi des cadres of 1907 introduced many important changes of detail supplementary to the loi de deux ans.
Historical inscriptions, royal charters and rescripts, despatches, private letters and the general literature afford welcome supplementary information.
Similarly in Europe they are often the property of the International Sleeping Car Company (Compagnie Internationale des Wagons-Lits), and the supplementary fares required from those who travel in them add materially to the cost of a journey.