Very old page from an exercise book in very neat manuscript with writing on both sides. The text describes in general terms, the System of Tides, i.e. as affected by the moon (diagrams etc.) No mention of Vietnam, rather of the Gulf Stream and the Atlantic Ocean - probably copied from a Vietnamese text book.. But not of Vietnam rather The Gulf Stream and Atlantic OceanRecovered from an abandoned bunker systempage from exercise book, system of tides, propaganda, nva/vc, psycological warfare, nva/vietcong, terry michael collie, 2790361, 7th battalion, 1st battalion, the royal australian regiment