Find the Exact Value of the Expression $$\tan ^ { - 1 } \frac { \sqrt { 3 } } { 3 }$$

Find the exact value of the expression.
- $$\tan ^ { - 1 } \frac { \sqrt { 3 } } { 3 }$$

A) $\frac { \pi } { 6 }$
B) $\frac { \pi } { 4 }$
C) $\frac { \pi } { 3 }$
D) $\frac { 7 \pi } { 6 }$