Chem Sources - USA / 
Edt. by M.J. Baker, Ch.L. Gardenberger & E.M. Giordano. 
 - Twentieth Edition 
 - Flemington, New Jersey :  Directories Publishing Company, Inc.,  1979. 
 - 730 p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Chemistry