Summary
Ole Christensen and Khadija L. Christensen (2006) Linear independence and series expansions in function spaces. Amer. Math. Monthly, 113(7):611–627. 
Bibtex entry
@ARTICLE { MR2252932,
AUTHOR = { Ole Christensen and Khadija L. Christensen },
TITLE = { Linear independence and series expansions in function spaces },
JOURNAL = { Amer. Math. Monthly },
FJOURNAL = { The American Mathematical Monthly },
VOLUME = { 113 },
YEAR = { 2006 },
NUMBER = { 7 },
PAGES = { 611--627 },
ISSN = { 0002-9890 },
CODEN = { AMMYAE },
MRCLASS = { 15A03 (42C15) },
MRNUMBER = { 2252932 (2007d:15001) },
DOI = { 10.2307/27642004 },
URL = { http://dx.doi.org/10.2307/27642004 },
}