Heller, R. (2004). Nghệ thuật giảm thiểu stress. Hà Nội: Văn hóa thông tin.
শিকাগো স্টাইলে সাইটেশনHeller, Robert. Nghệ Thuật Giảm Thiểu Stress. Hà Nội: Văn hóa thông tin, 2004.
এমএলএ সাইটেশনHeller, Robert. Nghệ Thuật Giảm Thiểu Stress. Hà Nội: Văn hóa thông tin, 2004.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.