Question: What is the width feet in meeters for the truss with a source of NBI (2009)?
SQL: SELECT "Width feet (m)" FROM "2-17565713-1" WHERE "Source (Year)" = 'NBI (2009)';

Question: What is the width for hte truss with a source of Zacher (1994)?
SQL: SELECT "Width feet (m)" FROM "2-17565713-1" WHERE "Source (Year)" = 'Zacher (1994)';