Differential Equations - Partial Differential Equations

http://tutorial.math.lamar.edu/Classes/DE/IntroPDE.aspx

http://fab.cba.mit.edu/classes/864.17/text/pde.pdf

http://issc.uj.ac.za/downloads/problems/partial.pdf

http://math.etsu.edu/multicalc/prealpha/chap2/chap2-4/printversion.pdf

https://ask.fxplus.ac.uk/tools/HELM/pages/workbooks_1_50_jan2008/Workbook25/25_1_partial_diffrntl_equatns.pdf

https://web.math.princeton.edu/~seri/homepage/papers/gws-2006-3.pdf

https://www.astro.umd.edu/~ricotti/NEWWEB/teaching/ASTR415/pres22.pdf

https://www.math.hmc.edu/~ajb/PCMI/lecture1.pdf

https://www.math.psu.edu/tseng/class/Math251/Notes-PDE%20pt1.pdf

https://www.math.ucla.edu/~yanovsky/handbooks/PDEs.pdf

https://www.math.uni-leipzig.de/~miersemann/pdebook.pdf

https://www.math.ust.hk/~machas/differential-equations.pdf

https://www.uni-muenster.de/Physik.TP/archive/typo3/fileadmin/lehre/NumMethoden/WS1011/script1011PDE.pdf

http://web.math.ucsb.edu/~grigoryan/124A.pdf

http://www1.maths.leeds.ac.uk/~kersale/Teach/M3414/Notes/m3414_1.pdf

http://www.csc.kth.se/utbildning/kth/kurser/DN1213/numme06/utdelat/kap10.pdf

http://www.it.uu.se/edu/course/homepage/finmet2/vt14/material/Lab3.pdf

http://www.math.chalmers.se/Math/Grundutb/CTH/mve030/1617/mve290-PDEs.pdf

http://www.maths.manchester.ac.uk/~kd/homepage/pdelec.pdf

http://www.math.stonybrook.edu/~mmovshev/mat341-fall18/Partial_Differential_Equations.pdf

http://www.physics.miami.edu/~nearing/mathmethods/pde.pdf

http://www.robots.ox.ac.uk/~jmb/lectures/pdelecture1.pdf

Re: Completeness, Orthonormality and Orthogonality in QM

http://depts.washington.edu/jrphys/ph248A11/QM3.pdf

https://homepage.univie.ac.at/reinhold.bertlmann/pdfs/T2_Skript_Chapter_3.pdf

https://pages.uoregon.edu/soper/QuantumMechanics2006/vectors.pdf

https://web.njit.edu/~venanzi/chem658/lecture/notes_Ch7.pdf

http://www.physics.usu.edu/Wheeler/QuantumMechanics/Quantum%20states%20as%20vectors.pdf

http://tid.uio.no/~finnr/notes/chap10.pdf

http://vergil.chemistry.gatech.edu/notes/quantrev/node19.html

http://www.matfys.lth.se/education/quantinfo/QIlect1.pdf

Completeness, Orthonormality and Orthogonality in QM

What are the properties of orthogonal functions?  

Purpose of it in power series expanstion?

https://physics.stackexchange.com/questions/295064/orthonormality-and-ket-expansion-for-uncountable-basis-kets-such-as-the-positio  

http://web.mst.edu/~parris/QuantumTwo/Class_Notes/GeneralFormulation.pdf   

https://ocw.mit.edu/courses/physics/8-05-quantum-physics-ii-fall-2013/lecture-notes/MIT8_05F13_Chap_04.pdf   

https://www.tcm.phy.cam.ac.uk/~pdh1001/thesis/node12.html  

https://www2.ph.ed.ac.uk/~ldeldebb/docs/QM/lect4.pdf  

https://en.wikipedia.org/wiki/Orthogonality  

https://arxiv.org/pdf/1709.07652.pdf

https://arxiv.org/pdf/quant-ph/9911046.pdf

http://www.physics.sdsu.edu/~johnson/phys410/lecture9of410.pdf

https://www.quora.com/How-do-you-explain-the-completeness-relation-in-Quantum-Mechanics 

https://physics.stackexchange.com/questions/241673/on-the-completeness-relation-in-quantum-mechanics/241677 

https://physics.stackexchange.com/questions/251803/what-is-meant-by-the-term-completeness-relation

http://iopscience.iop.org/article/10.1088/2399-6528/aa9fc0

https://www.youtube.com/watch?v=Wq0gYWJjtMc 

https://www.youtube.com/watch?v=LyyZJT5FXIY  

Orthogonal polynomial

https://www.encyclopediaofmath.org/index.php/Classical_orthogonal_polynomials  

https://www.encyclopediaofmath.org/index.php/Orthogonal_polynomials  

https://en.wikipedia.org/wiki/Orthogonal_polynomials

https://arxiv.org/pdf/1712.03155.pdf

http://fdslive.oup.com/www.oup.com/academic/pdf/13/9780198506720.pdf

http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=BA513EAFA987B3C7F36B658EBE3907E4?doi=10.1.1.760.2995&rep=rep1&type=pdf

http://www.math.miami.edu/~morsej/Articles/flj.pdf

http://galton.uchicago.edu/~lalley/Courses/386/OrthogonalPolynomials.pdf

http://arxiv-export-lb.library.cornell.edu/abs/1701.02709  

http://arxiv-export-lb.library.cornell.edu/abs/1801.09099  

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.237.7629&rep=rep1&type=pdf 

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.757.619&rep=rep1&type=pdf

Igor Kortchemski

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/geometrie/gimo.pdf

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/mc97-98-01feb.pdf  

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/IMO/imo (1990 - 2002) Hojoo Lee.pdf

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/arithmetique/pen2005.pdf 

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/inegalites/i2006.pdf  

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/inegalites/psine2.pdf  

http://igor-kortchemski.perso.math.cnrs.fr/olympiades/Problemes/inegalites/psine1.pdf