Perhaps you should try some spelling variations:
"tu can trinh kxy thuat san hoc" » "tu can tranh kxy thuat san hoc", "tu dan trinh kxy thuat san hoc", "tu van trinh kxy thuat san hoc", "tu can trinh ky thuat san hoc", "tu can trinh ly thuat san hoc", "tu can trinh ke thuat san hoc", "tu can trinh ki thuat san hoc", "tu can trinh my thuat san hoc", "tu can trinh ky thua san hoc", "tu can trinh kxy thuat toan hoc", "tu can trinh kxy thuat song hoc", "tu can trinh kxy thuat lanh hoc", "tu can trinh kxy thuat van hoc", "tu can trinh kxy thuat dan hoc", "tu can trinh kxy thuat san ho", "tu ban trinh kxy thuat san hoc", "tu cac trinh kxy thuat san hoc", "thu canh trinh kxy thuat san hoc"
"toc sach ngan ky thuat do hoc" » "toc sach ngon ky thuat do hoc", "toc sach nha ky thuat do hoc", "toc sach han ky thuat do hoc", "hoc sach ngan ky thuat do hoc", "doc sach ngan ky thuat do hoc", "thuoc sach ngan ky thuat do hoc", "toc sach ngan ky thuat o hoc", "toc sach nganh ky thuat do hoc", "toc sach nhan ky thuat do hoc", "toc sach ngan hay thuat do hoc", "toc sach ngan ky thuat co hoc", "toc sach ngan ky thuat do hoa", "toc sach ngan ky thuat du hoc"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("toc sach ngan ky thuat do hoc") or ("tu can trinh kxy thuat san hoc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("toc sach ngan ky thuat do hoc") OR ("tu can trinh kxy thuat san hoc")).
• Removing quotes may allow a broader search: (( toc sach ngan ky thuat do hoc ) or ( tu can trinh kxy thuat san hoc )).
• Adding a wildcard symbol may retrieve word variants: (("toc sach ngan ky thuat do hoc") or ("tu can trinh kxy thuat san hoc"))*.