The rules that use the vocabulary item "2s1" are:

<i_f_v-sing>

2s1 122mm howitzer

2s1 howitzer

swa 2s1 122mm howitzer

swa 2s1 howitzer

<i_f_v-pl>

2s1 122mm howitzers

2s1 howitzers

swa 2s1 122mm howitzers

swa 2s1 howitzers

<i_f_v>

2s1 122mm howitzer

2s1 122mm howitzers

2s1 howitzer

2s1 howitzers

swa 2s1 122mm howitzer

swa 2s1 122mm howitzers

swa 2s1 howitzer

swa 2s1 howitzers