in 1980 Ron Brown published a booklet called "A simple two-queen system". This should be available from English bee-book suppliers such as BEE Books New and Old (UK tel 01823 698781) or Northern Bee Books who will take payment in non-UK currency and can be contacted at [log in to unmask] The essential feature is to run two queens so as to get lots of workers ready for the main flow. Brian Gant