Discretization

http://code.activestate.com/recipes/579021-delaunay-triangulation/

Interpolation

• http://www.cs.rpi.edu/~flaherje/pdf/fea4.pdf
• http://www.sd.ruhr-uni-bochum.de/downloads/Shape_funct.pdf
• http://what-when-how.com/the-finite-element-method/fem-for-3d-solids-finite-element-method-part-1/
• http://www.uni-tuebingen.de/zag/teaching/environmental_modeling/S4B_FiniteElements.pdf
• http://www.colorado.edu/engineering/CAS/courses.d/AFEM.d/AFEM.Ch10.d/AFEM.Ch10.pdf
• http://www.colorado.edu/engineering/CAS/courses.d/AFEM.d/AFEM.Ch10.d/AFEM.Ch10.Slides.d/AFEM.Ch10.Slides.pdf
• http://www.colorado.edu/engineering/CAS/courses.d/AFEM.d/AFEM.AppI.d/AFEM.AppI.pdf
• http://www.code-aster.org/V2/doc/default/en/man_r/r3/r3.01.01.pdf
• http://www.researchgate.net/publication/267082822_Unified_isoparametric_3D_Lagrange_finite_elements

Integration

• http://arxiv.org/pdf/1411.1341.pdf

Hierarchial shape functions - https://www.math.vt.edu/people/adjerids/research/papers/basis.pdf