NP EN ISO 3767-4-1998 拖拉机．农用以及林用设备．花园或者草地上用到的机动设备．相关的控制标示．第4部分：林用设备的符号标示（ISO 3767-4-1993）
Tractors, machinery for agriculture and forestry, powered lawn and garden equipment Symbols for operator controls and other displays Part 4: Symbols for forestry machinery (ISO 3767-4:1993)