Perhaps you should try some spelling variations:
"so sach than ky thuat tien hoc" » "so sach than ky thuat tieng hoc", "so sach than ky thuat dien hoc", "so sach than ky thuat vien hoc", "so sach tham ky thuat tien hoc", "so sach han ky thuat tien hoc", "so sach tranh ky thuat tien hoc", "so sach than ky thuat tin hoc", "so sach than ky thuat tien hoa", "bo sach than ky thuat tien hoc", "co sach than ky thuat tien hoc", "hoc sach than ky thuat tien hoc"
"so sanh hanh ky thuat van hoc" » "so xanh hanh ky thuat van hoc", "so danh thanh ky thuat van hoc", "so ban hanh ky thuat van hoc", "so sanh hanh ky thuat san hoc", "so sanh hanh ky thuat va hoc", "so sanh hanh ky thuat ban hoc", "do sanh hanh ky thuat van hoc", "so sanh hanh kem thuat van hoc", "so sanh hanh ky thuat van hoa"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("so sanh hanh ky thuat van hoc") or ("so sach than ky thuat tien hoc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("so sanh hanh ky thuat van hoc") OR ("so sach than ky thuat tien hoc")).
• Removing quotes may allow a broader search: (( so sanh hanh ky thuat van hoc ) or ( so sach than ky thuat tien hoc )).
• Adding a wildcard symbol may retrieve word variants: (("so sanh hanh ky thuat van hoc") or ("so sach than ky thuat tien hoc"))*.