Perhaps you should try some spelling variations:
hoach xin » hoach dinh, hoach xay, hoach san
thao khoa » thai khoa, toan khoa, pham khoa
sach tinh » sach kinh, sac tinh, sach tranh
chat khoa » chat hoa, chai khoa, khat khoa
xin thao » minh thao, dinh thao, lin thai
khoa hoc » hoa hoc
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu hoach xin thao khoa hoc ) or ( tu sach tinh chat khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu hoach xin thao khoa hoc ) OR ( tu sach tinh chat khoa hoc )).
• Adding a wildcard symbol may retrieve word variants: (( thu hoach xin thao khoa hoc ) or ( tu sach tinh chat khoa hoc ))*.