Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuoc sinh
thuat mach » thuat tach, thuyet mach, thuat lanh
thuat sach » thuat lanh, thuat san
sach thai » sach tham, sac thai, sach tai
khoa cham » khoa kham, khoa cam, khoa chau
cham hong » pham hong, chan hong, pham hoang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach thai ((thuat mach) OR (thuat sach)) khoa cham hong~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach thai ((thuat mach) OR (thuat sach)) khoa cham hong".
• Adding a wildcard symbol may retrieve word variants: thuoc sach thai ((thuat mach) OR (thuat sach)) khoa cham hong*.