EPUB3-compliant way of providing vertically scrollable manga

Dear colleagues,

Everybody uses proprietary formats for vertically scrollable manga,
but there is an EPUB3-compliant way.  I wrote two articles about
it long time ago.

Creating Vertically Scrollable EPUB Manga
<https://docs.google.com/document/d/1_mab1YECyJegt5oZF8PmJl2RxZqcgPui4gnPksJ4yoA/edit>
How to Support Vertically-Scrollable EPUB Manga
<https://docs.google.com/document/d/1lPDFOpxet3Plt82ginR5D4LEiJ2FPjr07pRDb_wyjH4/edit>


Regards,
Makoto