[Getfem-users] Formulae in Getfem manual

[Dau Nguyen Van]

Dear members,

Could any one please show me a book or journal article ... from which the formulae of Getfem manual come?

For example I try to understand the formulae in at the following pages and would like to know if these formulae are explained in a book of any other references:

http://download.gna.org/getfem/html/homepage/userdoc/appendixA.html#ud-appendixa
http://download.gna.org/getfem/html/homepage/project/appendixA.html#volume-integral
http://download.gna.org/getfem/html/homepage/project/appendixA.html#example-of-elementary-matrix

Many thanks in advance,

Nguyen