'considerable endeavour' is correct and can be used in written English.
You could use it to talk about putting in a lot of effort to accomplish something, as in the following example: "John put in a considerable endeavour to complete his project on time."
Because of the cost and considerable effort involved in such an endeavour, the important first step is to thoroughly consider whether a genome sequence is necessary for addressing the biological question at hand.
"He has made a significant contribution to British business life through his firm, Bloomberg LP, and the impact of his considerable philanthropic endeavours in the arts and education is felt by Britons every day," he added.
The 1920s and 1930s were a period of considerable artistic and architectural endeavour and achievement, encouraged by the Mussolini regime, but political taboos have tended to hinder serious attempts to re-examine the art of the Fascist periods - until now.
As a consequence, such articles represent considerable waste in research funding and endeavour.
Problems of identifying and navigating services offered by health care, education and social services can be incredibly trying for parents, particularly mothers, who spend considerable energy and resources in these endeavours.
Mr Sharon, with his hatred of the not-quite-dead-yet Oslo peace process, will do his considerable best to frustrate Mr Tenet's endeavours.
There are considerable limits on how far government can or should endeavour to direct such measures.
The impact of the opening chorus Herr, unser Herrscher, delivered by the joint forces of the Cantamus Chamber Choir, the Wiltshire Music Centre Chorus and choristers from St Laurence School with a considerable body of sound, was testimony enough to a worthy endeavour.
"This has made evaluating the agreement a difficult and deliberate endeavour, and after deep study, careful thought and considerable soul-searching, I have decided I must oppose the agreement and will vote yes on a motion of disapproval".
Decolonisation also heralded a phase of state formation, in which newly established African states have endeavoured to instil a sense of national unity in ethnically diverse societies, which often created considerable internal tensions and has regularly erupted in violent conflicts (cf. Davidson, 1992).
