The Kama Sutra of Vatsyayana by Vatsyayana (PDF Download)
The Kama Sutra is an ancient Indian Hindu text written by Vātsyāyana. It is widely considered to be the standard work on human sexual behaviour in Sanskrit literature.
A portion of the work consists of practical advice on sexual intercourse.[3] It is largely in prose, with many inserted anustubh poetry verses. "Kāma" which is one of the four goals of Hindu life, means desire including sexual desire the latter being the subject of the textbook, and "sūtra" literally means a thread or line that holds things together, and more metaphorically refers to an aphorism (or line, rule, formula), or a collection of such aphorisms in the form of a manual.