It is an appalling industry and should be stopped.
As the previous person said, look at the web under "sex-slave trade", "child sex tourism" and you will find many articles on the topic.
One site that I suggest is <www.ecpat.org> and also <www.ecpat.net> as both these sites will take you to either the international, the UK or the Australia sites of "End Child Prostitution And Tourism" (ECPAT).
Prime countries for Child Sex Tourism are:
The Philippines -- with mostly Filipino girls but also from other countries. The youngest girls are usually around 8 for both vaginal and oral.
Thailand with girls from all over Thailand, but mostly from the North East, the North and the west close to the Burmese border with Burman, Karen, Kachin and Meo girls. The girls are usually about 10 and older.
Sri Lanka (Ceylon) with Ceylonese and Tamil girls and a few Indian.
Cambodia -- mostly with Vietnamese but a few Cambodian, Laotian and Thai girls.Girls are forced to have Oral sex from the age of 5 and start having vaginal sex at 9-10.
To a lesser extent in India (mostly with Nepalese girls).
There is very little sex tourism in Indonesia although brothels are numerous. The army runs brothels for their own members with some girls as young as 5 who are forced to have vaginal sex which usually kills them or severely damages the vagina and urethra (rupturing the lining between the two) causing the girl to leak foul smelling urine from her vagina.
The photo in the other section shows a Thai girl about 15-16 years old, and therefore is not a "Child prostitute".
Also, I feel that you need to define your terms with your article when you write it.
A Prostitute is a person, male of female, who engages in sex for money and who keeps the majority of the money for her/himself giving a small amount to the pimp for protection etc or to the brothel they work in for 'overheads' such as laundry of linen (towels, bedsheets etc), condoms, electricity, water etc. A prostitute may refuse a client, and can usually demand the use of condoms. They are usually above 10 years of age and often work until their late 30's.
A Sex-slave is usually a female, some as young as five, who have been either kidnapped from home or sold by their parents or a relative, or tricked into leaving home with the offer of a good job. A sex-slave is someone who engages in sex for money but never receives any of the money. She can be bought, sold, trafficked across borders, beaten up or even killed by her owners. She cannot refuse a client and if the client wishes to not use a condom, she cannot refuse. She is usually thrown out by her mid twenties if she is not already dead or infected by HIV-AIDS
A former TV news cameraman and journalist with over 30 years in the industry in Australia and Southeast Asia and have done numerous stories on "Child Labour".
Currently a SE Asian historian.