ebook webapp

I can create ebooks-webapps with these attributes:
a) automatically created table-of-contents expands on mouse position.
b) anyone can-refer to ANY part of the text.
c) internal links shows preview of the destination.

I wrote the required programming (https://synagonism.net/dirMiwMcs/dirTchInf/filMcsLhitp.last.html#idOverview)

EXAMPLES:
1) System of National Accounts 2008 (https://synagonism.net/standard/economy/un.sna.2008.html#idHeader)
2) Keynes General Theory of Employment (https://synagonism.net/book/economy/keynes.1936.general-theory.html#idHeader)
3) US-Constitution (https://synagonism.net/law/us/constitution.1992.html#idHeader)
4) my website (synagonism.net) is full of other examples.

cost depends on:
a) functionality wanted.
b) quantity of text.
c) type of text given.