Perhaps you should try some spelling variations:
tranh thuc » trinh thuc, trang thuc, thanh thuy
khan thong » khap thong, khau thong, nhan thong
cat phuong » cac phuong, cau phuong, xuat phuong
phap thong » phap phong, phap chong, pho thong
can tranh » canh tranh, tan tran, van ranh
sach thai » sach tham, sac thai, sach tai
thai thuc » thai thuy, thai tuc, tham thuc
hanh kho » hanh khu, hang khoa, hanh theo
kho khan » khoa kham, khoa than
thuc cat » thuc vat, thuc can, thuc cao
tu sach » thu sach, su sach, te sach
tu can » tu ban, tu cac, thu canh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu can tranh thuc hanh kho khan thong ) or ( tu sach thai thuc cat phuong phap thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu can tranh thuc hanh kho khan thong ) OR ( tu sach thai thuc cat phuong phap thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu can tranh thuc hanh kho khan thong ) or ( tu sach thai thuc cat phuong phap thong ))*.