Perhaps you should try some spelling variations:
"te sach trinh ky chuan hoa hoc" » "te sach tranh ky chuan hoa hoc", "te hanh trinh ky chuan hoa hoc", "te sach kinh ky chuan hoa hoc", "te sach trinh ky chuan ha hoc", "te sach trinh ky chuan doan hoc", "te sach trinh ky khuan khoa hoc", "te sach trinh quy chuan hoa hoc", "te sach trinh ky chau hoa hoc", "te sach trinh ky cua hoa hoc", "toc sach trinh ky chuan hoa hoc"
"thu sach nganh ky thuat song ho" » "thu sach ngan ky thuat song ho", "thu sach tranh ky thuat song ho", "thu cac nganh ky thuat song ho", "tu sach nganh ky thuat song ho", "thuat sach nganh ky thuat song ho", "thuoc sach nganh ky thuat song ho", "thu sach nganh y thuat song ho", "thu sach nganh xay thuat song ho", "thu sach hanh ky thuat song ho", "thu sach nganh ky thuat dong ho", "thu sach nganh ky thuat song vo", "thu sach nganh ky thuat cong ho"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("te sach trinh ky chuan hoa hoc") or ("thu sach nganh ky thuat song ho"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("te sach trinh ky chuan hoa hoc") OR ("thu sach nganh ky thuat song ho")).
• Removing quotes may allow a broader search: (( te sach trinh ky chuan hoa hoc ) or ( thu sach nganh ky thuat song ho )).
• Adding a wildcard symbol may retrieve word variants: (("te sach trinh ky chuan hoa hoc") or ("thu sach nganh ky thuat song ho"))*.