Thai ingredients?

I have a Thai recipe that uses Thai shallots and sour oranges, I have never seen these items (even in my Asian grocery store).

Do you know where I could find them or any substitutes? I have shallots but how are they Thai ones different??? Also, I have lemons %26amp; limes but how are sour oranges different?Thai ingredients?
Thai shallots are the same as Asian Shallots:



Asian Shallots are called 'bawang merah kecil' (small red onions) in Bahasa Melayu, an official language of Indonesia, Malaysia, Brunei, and Singapore, and "hom" (喔腑喔?- literally "fragrant") in Thai. In South East Asian cuisines, such as Thai, Malaysian and Indonesian cuisines, both shallots and garlic ('bawang putih', white onions) are very often used as elementary spices. Raw shallot can also accompany cucumbers when pickled in mild vinegar solution. It is also often chopped finely, then fried until golden brown, resulting in tiny crispy shallot chips called 'bawang goreng' (fried onions)in Indonesian language, which can be bought ready-made from groceries and supermarkets. It enhances the flavor of many South East Asian dishes, such as fried rice variants. In Indonesia, sometimes it is made into pickle which is usually added in variable kinds of traditional food. Its sourness increases one's appetite.



It is widely used in the southern part of India. It is called Sambar Vengayam in Tamil and Kochulli in Malayalam and is used in Sambar (a type of curry) and different types of kuzhambu(curry).



As a substitute, use a small red onion along with 1-2 American shallots.



http://en.wikipedia.org/wiki/Shallot

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A species of multiple uses, the sour orange (Citrus aurantium, L.), is also known as bitter, bigarade, or Seville orange. In Spanish-speaking areas it may be called naranja 谩cida, naranja agria, or naranja amarga. In Arabia, it is naranji; in Italy, melangolo; in India, khatta; in Samoa, moli, in Guam, soap orange.



http://www.hort.purdue.edu/newcrop/morto鈥?/a>



As a substitute use 1 lime and 1/2 an American orange.Thai ingredients?
If you cannot find Thai shallots then you may need to use more of the kind we have here. They are stronger in flavor. The article belwo says US Thai restaurants often use onions instead.



for the sour orange you probably need to add a lot of lime juice to a little orange juice. It is not going to be the same but should work as a substitute.