TY  - BOOK
AU  - Elwell D.,  .
TI  - Man-Made Gemstones / 
SN  - 0 85312 128 1
U1  - C21:(H19:164) 
PY  - 1981///
CY  - England : 
PB  - Ellis Horwood Limited , 
KW  - Physics
ER  -