My reseach notes "as a general rule, a gain on the sale of 'personal property' is US source income if the taxpayer is a U.S. resident and foreign-source income if the taxpayer is a nonresident." It further says "a gain on the sale of exchange of a US reap property interest is U.S. source income, whereas a gain on the sale or exchange of real property located abroad is foreign-source income. All other factors, including where the selling activities took place, are ignored. Pub 519 did not speak to foreign real estate owned by a US citizen. I am not convinced just yet but I sincerely thank you for your response.