Gass, Robert H. (california State University, Seiter, John S. (utah State University (1) Gass, Robert H, Seiter, John S (1) Powell Robert Powell, Conant Roger Conant, Collins Joseph T. Collins (1) Stebbins, Robert C., Mcginnis, Samuel M. (1) Bartholomew Eldredge, L. Kay (the University Of Texas Health Science Center At Houston), Markham, Christine M. (university Of Texas School Of Public Health), Ruiter, Robert A. C. (maastricht University, Fernandez, Maria E. (maastricht University (1)