Some books I can recommend for martial artists

I thought I could share some hints about books I read (some of them I have) that somehow I think are worth reading.

AIKIDO
Two books that have loose collection of quotes of O'Sensei:
The Secret Teachings of Aikido
The Essence of Aikido: Spiritual Teachings of Morihei Ueshiba
An amazing book by Kisshomaru Ueshiba:
The Spirit of Aikido. Truly deep, something you will be coming back to over years and finding it more and more deep and relevant.

MARTIAL ARTS/STRATEGY
Sun Tzu 'Art Of War' has multiple editions, I suggest finding the one with interesting commentaries. I used to have an edition with commentary of one USMC general and his views on view of strategy of modern Chinese warfare in relation to Sun Tzu.
Another of thise short but meaningful books is Musashi Miyamoto's The Book of Five Rings.
For me the most amazing thing I ever read (apart from Buddhist teachings ;-) was a book titled Heiho Kadensho. It's available in English under title The Life-Giving Sword: The Secret Teachings From the House of the Shogun. This book contains a series of dialogs of Zen monk Takuan Soho with one of shogun's ninja generals and one of greatest swordsman of the times - Munenori Yagyu.
I can also honestly recommend On War by Carl von Clausewitz. This is one of these classics that will never grow old.

NIHONTO
The knowledge of Japanese swords starts with The Samurai Sword: A Handbook by John Yumoto.
Then there is The Japanese Sword: A Comprehensive Guide by Kazan Sato.
Once you get drawn into the subject, one of the best books is The Connoisseurs Book of Japanese Swords by kokan Nagayama, who recently passed away.