catalog[2].title = Bumi Manusia
(*bp).title      = Bumi Manusia
bp->title        = Bumi Manusia
after bp->year = 1981, catalog[2].year = 1981

Walking the catalog with a Book*:
  [0] B4001  Laskar Pelangi (2005)
  [1] B4002  Filosofi Kopi (2006)
  [2] B4003  Bumi Manusia (1980)
  [3] B4004  Negeri 5 Menara (2009)
  [4] B4005  Cantik Itu Luka (2002)

Following the chain from head:
  Bumi Manusia
  Laskar Pelangi
  Cantik Itu Luka
head->next->next->data.title = Cantik Itu Luka
