TY  - JOUR 
T1  - Optical Studies of Undoped and Doped Wide Bandgap Carbide and Nitride Semiconductors
JO  - Brazilian Journal of Physics
A1  - Freitas, J.A.
A1  - Moore, W.J.
SN  - 0103-9733
UL  - 10.1590/S0103-97331998000100002
VL  - 28 
Y1  - 1998
PB  - Brasil 
ER  -