Perhaps you should try some spelling variations:
dang mam » dang nam, dang mau, dang mat
vat hanh » vat thanh, van hanh, va hanh
cua tre » cua te, cuu tre, cua triet
dang ma » dang mau, dang mat, tang ma
hanh va » hang va, hanh vi
va cua » va chua, via cua, ca cua
te cac » tu cac, ve cac, te cao
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te cac ky ((dang ma) or (dang mam)) hoi. hieu ((ve cam) OR (va cam)) thuc vat hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te cac ky ((dang ma) OR (dang mam)) hoi. hieu ((ve cam) OR (va cam)) thuc vat hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ky ((dang ma) or (dang mam)) hoi. hieu ((ve cam) OR (va cam)) thuc vat hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: te cac ky ((dang ma) or (dang mam)) hoi. hieu ((ve cam) OR (va cam)) thuc vat hanh va cua tre*.