Schur multipliers for group extensions and for Lie groups also
Where are they written for Lie algebras?



Schur `multipliers' for Lie algebras
Take a look at the [Ph.D. Thesis of P.G. Batten](http://www4.ncsu.edu/~stitz/Multipliers%20and%20Covers%20of%20Lie%20Algebras.pdf):


*Multipliers and covers of Lie algebras*, North Carolina State University, 1993, dir. by E. Stitzinger; [MathSciNet Link](http://www.ams.org/mathscinet-getitem?mr=2688923).


