found: Work cat.: Soars, F. The modern approach to lawn bowls, 1969.
found: Cuddon, J.A. Intl. dict. of sports and games, 1980(Bowls: there are 2 kinds of bowls played in the open: crown green and lawn. Both are played on the grass. Lawn or flat green bowls is played on a level green or lawn)
found: King, N. The game of bowls, 1975:p. 138-148, glossary (bowling on the green is an American expression to distinguish lawn bowling from the game of bowling at pins in alleys)
found: Hennepin(Lawn bowling)
found: World Book(Lawn bowling)
found: Britannica 15:under Bowling (Bowls; lists most widely played form of bowls as flat green; variation sometimes referred to as East Anglian bowls)