i books storing PDF question

hello

i recently moved from my old iphone 5 to a new SE. i first did a backup of the old phone via hard-wire and itunes on my PC. while my notes and pictures etc. came over to the new phone all the PDF's i had on my old phone did not?

additionally i do not see an ibooks icon when i log onto icloud.com or on itunes so i cant even see what is backed up?

thanks