Equation, Formula, Matrix, etc.
Inline-formula (between text words)
http://dx.doi.org/10.4196/kjpp.2014.18.3.217
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4071174/
Long fraction (longer than a line)
http://dx.doi.org/10.5607/en.2015.24.1.41
http://enjournal.org/DOIx.php?id=10.5607/en.2015.24.1.41
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363333/
Matrix
http://dx.doi.org/10.5230/jgc.2015.15.1.29
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4389094/
Equation within table footnote (e.g., Table 1)
http://dx.doi.org/10.3348/kjr.2015.16.2.286
http://www.kjronline.org/DOIx.php?id=10.3348/kjr.2015.16.2.286
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4347264
Multiple layer fraction (e.g., Root)
http://dx.doi.org/10.3348/kjr.2015.16.2.286 --> Table 1
http://www.kjronline.org/DOIx.php?id=10.3348/kjr.2015.16.2.286
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4347264
Notations with superscript/subscript values (e.g., Integral)
http://dx.doi.org/10.4258/hir.2014.20.3.191
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141133/
Long formula (longer than a line)
http://dx.doi.org/10.4162/nrp.2015.9.1.71
http://e-nrp.org/DOIx.php?id=10.4162/nrp.2015.9.1.71
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4317483/
Equation number in parenthesis, in brackets (e.g., (equation 2), [3])
http://dx.doi.org/10.4196/kjpp.2015.19.2.167
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4342737/
http://dx.doi.org/10.5230/jgc.2015.15.1.29
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4389094/
Underscript/Overscript (e.g., Sigma),
http://dx.doi.org/10.3346/jkms.2015.30.5.625
http://jkms.org/DOIx.php?id=10.3346/jkms.2015.30.5.625
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4414648/
Fraction
http://dx.doi.org/10.4168/aair.2015.7.1.83
http://e-aair.org/DOIx.php?id=10.4168/aair.2015.7.1.83
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4274474/
Various equations
http://dx.doi.org/10.4097/kjae.2013.65.5.385
--> Appendix 1
http://ekja.org/DOIx.php?id=10.4097/kjae.2013.65.5.385
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866333/
World J Mens Health 2015;33(1):1–7 (Published online 2015 Apr 23)
http://dx.doi.org/10.5534/wjmh.2015.33.1.1
http://wjmh.org/DOIx.php?id=10.5534/wjmh.2015.33.1.1
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412002/