Tangs, OG, BHG, Robinsons and Metro (just depends on the brand you are looking for)
Can try ntuc finest, isetan, takashimaya :)
Try those big supermarkets like Giant ...
can get from most department stores
Can try Bugis BHG, OG as well.
Most department stores have
I got mine from Robinson
Takashimaya or isetan
can try kiddy palace
Isetan, ntuc, online