The names are spelled how they are in the books.
Please do not get mad at me if I got something wrong, just tell me about it in the comments.
I used the abbreviations of the book titles. If you don't know them:
TLT - The Lightning Thief; SoM - Sea of Monsters; TTC - The Titan's Curse; BotL - Battle of the Labyrinth; TLO - The Last Olympian; TLH - The Lost Hero; SoN - Son of Neptune; MoA - Mark of Athena; HoH - House of Hades; BoO - Blood of Olympus; THO - The Hidden Oracle; TDP - The Dark Prophesy; TBM - The Burning Maze; TTT - The Tyrant's Tomb; ToN - Tower of Nero; SoS - Sword of Summer; HoT - Hammer of Thor; SotD - Ship of the Dead; TRP - The Red Pyramid; ToF - Throne of Fire; TSS - The Serpent's Shadow.