Go through your results for flights to Phnom Penh in Cambodia with Netflights. Although Singapore Airlines usually has the best prices, it's best to double check what's available for your travel dates.
If you don’t have set dates for when you want to fly to Phnom Penh, try searching by month – that way, you can compare airfares throughout the year.
So, if the flights to Phnom Penh don't work for you, you could always try searching for flights to other airports in Cambodia.
Looking at a few different departure airports will give you even more choice. See what you can find. And remember, it's best to book your flights in advance wherever possible.