The Donkey Kong Country: Tropical Freeze Walkthrough reveals the location of every KONG Letter and Puzzle Piece in the game.  Can't find one? 
3-5 Twilight Terror - Donkey Kong Country Tropical Freeze Guide - IGN
2-6 Wing Ding - Donkey Kong Country Tropical Freeze Guide - IGN
5-5 Jelly Jamboree - Donkey Kong Country Tropical Freeze Guide - IGN
Donkey Kong Country: Tropical Freeze - Part 33 Sea Stack Attack 4-5 100% Walkthrough!
Donkey Kong Country: Topical Freeze Guide - Collectibles: Stage 5-A, Beehive Brawl
Donkey Kong Country: Topical Freeze Guide - Collectibles: Stage 5-A, Beehive Brawl
Donkey Kong Country: Tropical Freeze Review (Wii U)
Donkey Kong Country: Tropical Freeze: Prima Official Game Guide: von Esmarch, Nick, Van Grier, Cory: 8601410565862: : Books
4-5 Sea Stack Attack - Donkey Kong Country: Tropical Freeze Walkthrough - Neoseeker
Donkey Kong Country: Tropical Freeze Guide - Collectibles: Stage 7-1