The Zheng He voyages? This book is for you then. It's a bibliography of a wealth of primary and secondary sources (in latest editions, where applicable) in a multitude of languages, all around this subject. It's not terribly recent (pub. in 2013) but it'll serve you well.

I'm assuming you're a newbie to this topic, and want purely eyewitness records to start. In that case, I'd point you to to the accounts by Fei Xin, Gong Zhen, and Ma Huan, all of which you'll find enlisted in chapter 1. They're all Chinese officials who accompanied Zheng on his expeditions.