National RiverWATCH.
De'Ath, Jane.
WATCH.
Slough : Richmond Publishing for WATCH,
c1991.
Contents: 1 booklet -- 1 poster -- 8 instruction/information sheets -- 1 badge -- 4 pH indicator strips -- 2 hardness indicator strips -- 2 nitrate indicator strips -- 1 thermometer -- 1 riverwater transparency disc.