[jacquesm]

This is a prettified version of the original which is available here:

http://www.pianopractice.org/ , suggest a link change.

[nuclearnice1]

What do you see as the advantage of the “ugly” version?

More up to date?

[mkl]

http://www.pianopractice.org/ has the third edition from 2016, but this version is based on the second, from 2009. The third edition has many additions.

[kzrdude]

More canonical

[jacquesm]

HN as a rule tries to link to the original source of something when it is available.