Pruning Bougainvillea is a long process, but worth the adventure. Here's how you can do it too. There's a video to guides you along.
Bougainvillea Pruning Tips: Everything You Need to Know
How to Prune Bougainvillea: 8 Steps (with Pictures) - wikiHow
How to Plant, Grow, and Care for Bougainvillea Plant
Does Bougainvillea Grow Fast?
Pruning
Pruning Bougainvillea: Getting This Flowering Machine to Bloom
Bougainvillea Secrets: Sharing All I Know About This Colorful Plant
PLANTanswers: Plant Answers > Growing Bougainvilleas
Bougainvillea Secrets: Sharing All I Know About This Colorful Plant
Pruning Bougainvillea: Getting This Flowering Machine to Bloom
How to get flowers on my Bougainvillea - Gardening & Landscaping Stack Exchange
How to Prune and Trim Bougainvillea Plants My Bougainvillea glabra is a flowering machine. It puts out a big show of magenta/purplish color off and on for 9 or 10 months
Bougainvillea Species Guide - The Blooming Bonsai – Bonsai-En
The Bold, Brash, and Beautiful Bougainvillea - HubPages
How to Prune and Trim Bougainvillea for Maximum Bloom