Webster, Frederick E.; Webster, Frederick E. (). Industrial marketing strategy / Frederick E. Webster. New York : John Willey, 1979: .
Webster, Frederick E.; Webster, Frederick E. Industrial marketing strategy / Frederick E. Webster. New York : John Willey, 1979: ,
Webster, Frederick E.; Webster, Frederick E. Industrial marketing strategy / Frederick E. Webster. New York : John Willey, 1979: , .